Hi. I always use subtitles in my movies and the color options that are available are too bright. I'm also planning on changing to OLED and I think this will be a much bigger problem with more contrast.
Any of the above would be a solution for me and maybe others. Transparency appears to be the best, easiest option for all type of uses. Custom colors is a little too much, but it could solve it too. And the other one is to add some others presets with the same colors with less brightness. I don't think many people use other than white or yellow, it could be a lot more useful to have different presets for those.