I'm colorblind as well and what's fascinating to me is that this is the second AI created chart in a week I've seen that I can't read. Surprisingly I've found such agressively colorblind-unfriendly charts to be far less common when created by humans.

Out of curiosity, what colors (or text treatments) do you personally prefer to confer "gain" and "loss"?

It's not about preference, but about being able to see the differences in the first place, so any sufficiently contrast combination should work.

If you turn on the color filters in accessibility settings in macOS you can see what the contrast could look like to a colorblind person.

I don't have any color discrimination deficiencies, but it is my understanding that for various types of signage, the move has been towards RED=bad/danger/etc, and BLUE (instead of green)=good/safe/etc.

For color deficiencies, different lightnesses are safe e.g. dark for loss and light for gain (could be dark reds for loss and light greens for gain, but don't mix the lightnesses). Other options are icons/shapes (like up/down arrows) or pattern fills (like stripes for loss).

The general trick is you can rely on differences in color lightness, patterns, text and icons, but not differences in color hue. The page should be usable in grayscale.

Just curious, are there browser extensions that automatically can alter colors on a webpage to make them colorblind friendly?

Reminds me of trying to pick an available campsite on Parks Ontario.