Or two different shapes, because there are too many different color blindnesses. Board games started marking counters many years ago. Sometimes their colors are so similar even for non color blind people. I couldn't get a black from dark blue counter two nights ago, the light at the table was not great. And yellow looked a pale gray.

Examples for the game: the red stone could have a empty circle mark on the top it, the green one could have a circle with a dot inside. The destination squares would be marked with the empty circle and the dotted circle.

Oh, different shapes would be even better!

I have made a very quick-fix for colorblindness at https://kuboble.com/beta/

I'll try to come up with something better in the long term

The rule of thumb for this sort of thing is to never rely on color alone to convey important information. Shapes and patterns and textures are much preferable to simple color variations.

good call. A triangle and square in the middle of each circle would eliminate the need for color all together.

Thanks, looks much better. Ideally we could choose the two colors from a set of four or five colors.

Another option would be to use different forms, e.g. a round stone combined with a square one.

Anyway, nice game!

Looks like you've reverted the changes at some point today. Which is a definite productity win for me!

I have made it configurable in the settings

I also had this experience, thank you for fixing it so quickly. The game is fun!

Yea, even better: distinct iconography.

A circle and a triangle, for example.

This would be great. It looks like at the top end there might be a third stone. So square, triangle, circle. And where they go on the board marked with the same shape would be very intuitive even with no color at all.

I think square, circle, octagon would make the most sense. Or maybe diamond (rotated square) instead of octagon. That way adjacent stone would always touch.