FreeGameDev

A lot of games, especially older ones, use lots of colours as part of their gameplay. Older games have things like palette swapping, or colour-coded stuff (like keys).

Just recently it occurred to me that doing so is bad for colourblind users. Check out these doom keys as seen by red-green blindness:



Those keys are supposed to be blue, red and yellow. There's a bit of brightness variation between red and yellow but it's very subtle, especially for the smallest icons at the bottom. If you're still not convinced, here's a pop quiz: what's the colour of these doors, red or yellow?



So have you encountered a situation where something is unclear for colourblind users, and how did you get around it? Is there an open source game that could do with better accessibility for colourblind users?

Not the dev, but frozen bubble's colorblind mode adds shapes inside the bubbles like crescent moons to help tell them apart.

That reminds me, a year ago I helped out on FreeBlocks, a tetris attack / bejewelled clone, and it initially had the same problem - the blocks were identical except for colour. I managed to convince the author to add a shape inlay. See before/after pics:





I would have preferred it if we went further and had different shapes altogether, like bejewelled or animatch do, but I guess doing that will contradict the games name

SuperTux has this problem both with flowers and map spaces, and with the colored light puzzles. I solved this in ReTux by no having the colored lights and by using the animated blue space for all unsolved levels. (The flowers aren't a huge problem in ReTux because I only used two of them and the ice flower is noticeably brighter than the fire flower. Also, ReTux's design makes it possible for you to check at very little cost by shooting.)

I avoided this problem in Pacewar by adding a "colorblind mode", where shapes are placed over both the victory meter and the ships to distinguish the teams.

I still haven't figured out a way to fix the Project: Starfighter bullets in a way that doesn't look ugly (and it's important since there tends to be quite a lot of bullets on the screen, but only the red ones are dangerous to you). It needs to not make the bullets substantially larger and preferably shouldn't change the size at all. I would be open to any suggestions.

onpon4 {l Wrote}: still haven't figured out a way to fix the Project: Starfighter bullets in a way that doesn't look ugly

Have you tried reducing the bullets to grayscale and then tweaking the colour versions until the greyscale ones are distinguishable?

No, that's not something I've considered. I suppose that would have to be an option if I do it that way (since gray bullets would look quite bland to non-colorblind players, I imagine). Thanks for the suggestion.

onpon4 {l Wrote}:No, that's not something I've considered. I suppose that would have to be an option if I do it that way (since gray bullets would look quite bland to non-colorblind players, I imagine). Thanks for the suggestion.

I'm not saying make the bullets grayscale. I'm saying try turning them grayscale (in an editor) to see the difference, and then tweaking the colours (which would be IG) until you can distinguish their grayscale equivalent.

Yeah, that could be possible, too. I don't know, though; dark green is kind of ugly, too (it would have to be green that's darkened since darker colors are not as visible against the dark backgrounds).

Some Free (with a capital F) pixel shaders could be useful for debugging...

onpon4 {l Wrote}:Yeah, that could be possible, too. I don't know, though; dark green is kind of ugly, too (it would have to be green that's darkened since darker colors are not as visible against the dark backgrounds).

Got another idea. Animate the bullets. You could do a simple pulse animation. Faster pulses = your bullets. Slower pulses = their bullets.

Or another idea. Outline one side's bullets. Can use 2 shades of the same colour that way.

Thanks for those suggestions. None of them are simple due to Starfighter's coding, but I'll look into those solutions when I get to addressing the problem.

Or a final suggestion - different shapes. One squarish (X-ish), one round?

That one is just as difficult as outlines. Starfighter bases its collision rectangles on the size of images, and bullets are only two pixels high. So to do something like that (and that does seem like it would be ideal), I'll need to change Starfighter to use a fixed bounding box for bullets. Anyway, thanks again; I have a few different ideas to try now.

Ok, one final suggestion then.



Or lined instead of checked:

That was actually the first solution I tried. Unfortunately, it's no good; the bullets move quite fast, so pixel-level differences like that are not discernible during gameplay.

Don't worry, though. I'll get it fixed somehow. It's just a matter of when I get to it.