Sorry for the troubles. On a Mac, in the System Preferences under the Accessibility tab you can invert the colors or use a gray scale if that might work. I am colorblind also, but more with blue hues so I haven't noticed any issues. Not a great answer - but this is also a great time to encourage them to observe other things besides color to recognize "keywords" - I've been pulled over for "running" red lights that were blinking and I couldn't tell the position - so there are always other ways which you can tell something - but depending on the age that's not ever easy.
Are the colors easier to differentiate in Scratch or SNAP? Those might be solutions, if the color modifications on a Mac (or similar on a PC) don't work.
Please continue to post about this issue - your student most likely isn't - and won't be the last to have this issue and it is important we get feedback for future students (and a better product... right now we are in the Try > Reflect part of the PSP!).