It's so upsetting. I love the high contrast but everyone (including people I know in person) hate it. I don't know what to do but I'll think of something. I want eye popping features that make this render stand out and look stunning but I'm probably going to need a new method of achieving that.
If you use coarse contrast settings sure you will affect the image especially in that particular screen where you don't really need too much of it. Why not use small settings. Or even better, use what YOU like ! Or you can release 2 versions of your game, one with high contrast and label it "High Contrast Edition"

and one with your original settings. Or even better dynamic adjustments of bright, contrast, gamma, as in most games, but unfortunately not possible with GameMaker.
Don't worry about what people think, in the end, whatever you do, some people will tell you that your game sucks, some will love it, some will break down every pieces and comment on them......Now your last contrast adjustments, if you really think it looks fine, then you have a bad monitor ! or bad eye sight (or both!)
BTW I received your PM I tried replying to it to set things clear but it doesn't fucking go through, been trying several times and it won't let me, so fuck that

Nice to see that some people are at least using GM to make good games and not always the same ripped sprites/blocky sprites and same old same old shite. I'd love to try your game and give some feedback on it if you want.