Good reason to wear a thong of bright or contrasting color, just so people don't assume you are nude and start a kerfuffle.

 JM,
True, but in some locations you don't want to have 10-mile orange colored suits either to draw attention....lol

Solution:  basic black!  I've worn my black Muscleskins classic bikini at my health club pool a lot lately, feeling very comfortable.  Just got the same suit in orange, but am disinclined to wear it there since it screams for attention.  Not my style in that conservative setting, so I'll save it for the beach when a string or thong isn't appropriate (that's rare at the venues I frequent). 

 It is good to have a color that contrasts with your skin.  I did not say it has to be orange, but now you come to mention it, the longer I live in the tropics the more I like bright colors. I enjoy wearing thongs with bright or fluorescent string sides. Many of my thongs are more like g-strings, so if the only thing people notice is bright or high contrast then they are more likely to assume I am wearing something and not naked. Which is good, because then they are less likely to complain or call the police. Some of my fav thongs have narrow orange or yellow side strings which I often wear them on gray days when the colors pop.

My most embarrassing moment was before I'd actually got into a swimsuit. I took my younger son (at the time aged about 6) to the local municipal pool. We were running late and I rushed round getting our swimming stuff together before we jumped in the car and rushed off. In the changing rooms my son changed quickly and I stripped off and pulled my swimsuit out of my bag only to find I had packed my red Hom thong rather than my red Hom micro....

So I'm stood there naked (& fully waxed) holding up a red thong swimsuit in a very busy changing room, trying to decide whether to put it on and brazen it out or pack up and go home....

Rather wimpishly I chose the latter, as I didn't want to risk getting chucked out with my son of what was a busy pool with lots of families. Very embarrassing!

I had post somewhere the time when at South Beach my two sisters saw me walking wearing nothing but a thong by the first time in public. I was really embarrass but they were ok with it but was not as embarrass as this other time. 
My ex girlfriend who encouraged me to thong in public since we where young teenagers used to live in a private residential area where they had a pool. She used to invite me to enjoy the sun and for a swim in our thongs when she knew her family was not going to be around. Normally there were not a lot of people there so no one bothered us. 
This one time her family had a trip so as soon as they went to the airport we put on our thongs and went to the pool. We normally used shorts and shirt to walk all the way then take everything of pool side. After about an hour later we were enjoying the sun having a swim and suddenly we saw her three little sisters with two aunts and her mom walking into the pool area disappointed because they lost the fly. Luckily for me her dad just dropped them off and go. 
My ex and I were inside the pool so her two aunts and mom sat down to chat just where our clothing and towels were while her sisters went to put on her swim suites. My girlfriend got out of the pool to give a hello kiss to her aunts that were mature women and I just stayed there not knowing what to do. I was already embarrass for the situation and had not even started. That was the first time her aunts saw her wearing a thong. Her mom did know about it and didn´t mind but hide it from her dad. One of the aunts told her that if she was not to young to wear that but the other aunt and her mom started telling her that was normal in this days and ended saying she looked really good. 
I think by that time they all had see I was swimming with a small swim suite. It was a small pool not much of water cover. I had not give my back to them and tried to stay low. The sisters jumped into the water so my ex did too and we started playing some child water sports with them. I think my ex was enjoying the situation of me being with her family wearing a thong. I kind of did but I was really nervous.  
Time passed by and never saw the opportunity to cover up. Suddenly her mom gets off the phone and tells that dad is coming. My ex jumped out the pool graved her stuff and a towel and went inside a restroom. I did not have choice but to get out. I used the pool stairs that were next to them showing my back. They all stared and the aunt that told my ex she was to young was like oh I see its fashion. I got all red flesh but made me comfortable so I just dried myself next to them with out covering at all. My ex took my shorts when she ran away probably in porpoise so I just putted on my shirt and stayed talking to them like that for about five minutes. She gave me my shorts just minutes before her dad arrived. She was kind of laughing knowing how open minded her mom was. They did not say anything to my ex later but I still had a bad time.
 

I dosed off while sunbathing only to wake up with a pretty substantial @@@@@@ straining against my g-string.  I turned over and waited for it to subside but it was pretty obvious that the people around me had noticed.  It wasn't such a big deal since it was a nude beach, but I still had that feeling of embarrassment that I got as a kid going through puberty.

We were out with friends many years ago on a bar run.  At the last bar, I went to moon one couple that was sitting in a car and flashed my thong by accident.  These were my vanilla friends that basically teased me for a while.  I was young and very embarrased.  The female part of the couple still looks at me with that look, especially when she drinks.  She winds up telling me I am so good looking. The husband laughs it off. ;)

I am slowly keep less in touch with those Vanilla friends

 Hilarious, but obviously very embarassing!

It was before I got married. I used to stay alone in the flat. I woke up a fine morning and was getting ready for office. Came back from shower and noticed that I am out of my clean underwear!! I can never think of wearing same undie again. So, I kept on searching for a clean discarded brief or thong. Suddenly, a thong caught my eye. It was black cocksox enhancing thong. I normally wear it when I am with my gf at home. I thought its ok to wear it to office. It was a BIG MISTAKE! I wear formals to the office. And trust me, formals and cocksox dont go together! There is so much bulge in cocksox that only denim jeans can cover it. Anyways, I reached office and was very nervous and kept looking down there. I noticed it protruding more than a little. I was nervous whenever anybody encountered me standing. I tried not to walk too much that day. It was all going nervous and then a female colleague of me said "You look not much in control today". I felt so embarrassed that I have never ever worn cocksox again with formals

 About 15 years ago I lived alone on pretty quiet street. I came home late one night in the middle of summer and  I just couldn't stand being in my sweaty clothes anymore but I still had to take my dog out. So I stripped down to my 2Xist y-backs and walked out to the back yard. Like I said it was very late and the street is generally quiet anyway but sure enough the only other person around just walked up and started talking to me. I was totally caught off guard. I turned my back to the wall of the house but the stranger had already seen everything and the pouch was all the coverage I had on the front. He may have been drunk which made feel a little better but he wouldn't leave. He only left when my dog came up to us, she was super sweet but big enough to be imposing, especially in the dark.

Not actually a thong, but I went to a pool party where a bikini was an appropriate suit to wear.  It was a last minute invitation so I grabbed something in a hurry and put it on.  Turned out to be a novelty suit sold for a short time some years ago by DMK featuring a Hawaiian print solid back but a black see-thru mesh front.  After two hours of getting some interesting looks I realized what I had on.

 I was laying out at a pretty secluded beach on Hawaii. I fell asleep on my stomach. I woke up when I thought I heard laughter, instead it was a navy helicopter hovering about 30 ft from me. A large ship was just off the shore. The helicopter circled between me and the ship a half dozen times. It wasn't too embarrassing, but I thought it was similar to the first posts experience. 

 My most embarrassing moment was when I was visiting my sister and her family. It happened one morning when her kids got up and decided it would be fun to jump on uncle. Usually when I stay with them I sleep in some night wear just in case the ride to come in but on this trip I had forgotten to bring the nightwear and I slept in one of my thongs with a tank top as I normally do at home. I was a little worried that they may come crashing in so I locked the bedroom door. Well morning came and the kids came jumping in on me jumping up and down In night shorts and undies. One of them jumped under the cover pretending that they needed to hide from ghosts. Good thing it was dark under the covers as they didn't notice what I was wearing. Not knowing what to do I hid under the sheets. My sister poked her head in and said breakfast was ready. I said I would be up in a moment and the kids should run up. But the kids wouldn't have it. Uncle get out of bed they said. We want you to jump with us. I then said that uncle was only in his underwear. Then they said we don't care we are in our underwear to!  I then said that you probably will not like my style of underwear. That was the wrong words. They ripped the covers off of me and they saw my in just my thong. The only good thing was I was wearing a basic BVD cotton thong so it didn't look to weird to the kids from the front anyway. They then said  nice undies they don't look weird. Get out of bed and jump with us. So I got up facing towards them so they wouldn't see the back right then my sister looked in on us and said come on guys let's go. She then went up to the kitchen and so far no one notice I was wearing a thong right until I notice that the kids where now behind me and the oldest on said your butt is huge uncle. It's poking out from your underwear as they giggled. At the same moment the younger kid opened my suit case and grabbed a pair of Laser cut thongs and threw it in the air and continued to do that with all the clothing in my suit case. I ran over and said to stop doing that. The oldest one picked up one of my thongs that happen to be one of my TXM super stretchy red thongs and said I like these undies uncle they are so stretchy but why are all your undies missing the back!!!?I didn't know what to do I was super embarrassed and just said that's just the way my underwear is. I then said let's go up for breakfast and sent them up. I was scared that my sister and her husband where soon going to ask me the question after the kids spilled the beans. I went up stairs and the kids said I uncle funny pants and giggled. I was mortified. But that was it they never mentioned it again and my sister never asked about my underwear. The next couple of days went by and no mention at all about my underwear. Phew!!! That was my most embarrassing moment.  

I had an experience that could have been very embarrassing; however, in the end it turned out to be actually very funny and not embarrassing at all. But this is probably cause I kinda didn't experience directly myself. I'll explain:

My wife told me that few days ago she was at her best friend's house. Her friend has two kids. It came that my wife was sitting on the couch with the oldest kid (8 years-old) and they were looking at the pictures on her iphone. Suddenly the kid, who had her phone in his hands, saw a picture of our last holiday in Spain where I was walking on the beach, my back turned, wearing nothing but a Joe Snyder rio thong! Of course even if the picture was from behind, the kid understood it was me.
She told me that the kid simply asked her:"Why is he wearing ladies underwear?" (I don't think the kid knows the word "thong"). My wife handled it very well and gently explained to him that it wasn't female underwear and also men can wear skimpy panties. The kid didn't make further observations and than they went playing or doing something else.
It seems like the kid didn't give importance to the thing and he probably hasn't told his mother about it.

An observation I can make is how kids are deeply influenced by the surrounding culture. I don't think someone directly tell to kids that thongs are for women; however, this might be what they learn by observing their parents or other adults and also from advertisement and media.