The first condom I ever saw was blue.
I was in third form, surrounded by 20 other kids, and we were being taught by our P.E. teacher how to put a condom on an inoffensive, phallic-shaped plastic educational tool.
I don't think I've ever seen a coloured of flavoured condom out of its packet ever since. Novelty condoms have never really made sense to me: why you'd want your penis to resemble a Christmas tree is confounding.
Arguably, there are noble safe sex reasons for employing novelty condoms. Some STIs can be transmitted through unprotected oral sex. Chlamydia, Gonorrhea, Syphilis, Herpes/HPV are all possibilities (but there's almost zero risk of contracting HIV in this way, FYI). A strawberry or banana flavoured condom theoretically makes safe oral sex more appealing - maybe there's supposed to be something appealing about bubblegum flavours.
When you look online, the marketing spiel for coloured condoms seems to be all about "impressing your partner". "Need to add a little colour to your sex life?" asks one condom manufacturer. "Ready to impress your partner by exceeding their sexual expectations with flying colours?" claims another.
There might be something to this, because sex should be all about ensuring your partner is satisfied. Some people, for example, love certain colours. I've met people obsessed, even, with colours like purple or green - literally everything they wear is a shade of it. Why not extend that colour affinity to the more private aspects of your life? You're definitely not hurting anyone.
The first coloured condom was introduced to the market in 1949 in Japan, but it wasn't really until the AIDS epidemic began to abate in the late 80s and early 90s when novelty condoms became popular. For that reason, coloured and flavoured condoms probably began as part public health issue, part commercial opportunity.
Condoms in the 1990s, finally accepted as a necessity and required part of a safe sex life, needed a little more pizazz to be widely sellable. Almost every major condom brand began selling coloured, flavoured, and textured products; making them available everywhere from supermarkets and petrol stations to sex shops alike. If you're around my age (I'm 32) you probably remember the "assorted" box of condoms that were available: a venerable miscellany of colours and flavours; a Cadbury Favourites box of testers for the bedroom, if you will.
As the decades moved forward novelty condoms became less about look or taste and more about feel - today if you're not buying the standard clear latex type, you're probably after the ultra-thin kind that are supposed to offer a "more natural feel".
Coloured condoms might not have a huge future ahead of them. In the UK in 2015 the concept of a condom that would change colour if it detected certain STIs was developed. It was never put into commercial production, and whilst attracted a lot of praise for its ingenuity at the time, also came with some criticism (e.g. "the point of condoms are to prevent disease transmission, which they do incredibly well, not to test for it").
If coloured and flavoured condoms are your bag, they're still readily available though. If you're not into them, but come across them anyway (we all have emergencies!) it pays to remember something. No matter how comical or silly they might make the wearer feel, a blue, or yellow, or red condom is certainly better than no condom at all.