Add/change a color-blind friendly option for the muscle load graphics

Roughly 9% of people (!) have some form of red-green color blindness (including me). Please add an option (or change the default color) to not use only red and green in the muscle load graphics, as those colors are essentially indistinguishable for many people. Use something like blue or red, etc. This is a really, really easy thing to do, and makes quite a few people happy! (and probably all non-colourblind people do not even understand why this might be an issue... 😊) I am not sure if there are more uses of red and green (they look the same to me), but I do know of the muscle load diagram at least as my partner pointed that one out to me. Thank you!)