I dont know if any of you had a colour blind friends who play tenanged, but I do have a problem with differenciating colour. It is not a serious colour blind though. If you do a research on colour blind, there's a lot type of colour blind, mine is not that serious.. I can still differenciate red and green (that's why i got my license) but sometimes, it hard for me to differenciate colours. For example, when taking electronic course in school where I have to look for the resistor colour, it took me a while to determine the colour of the resistor.
And the same goes with jewel challenge! I found it hard to differenciate the colours in jewel challenge and I used it as a reason for me not doing well in jewel challenge lol!
I discovered my colour blindness when I was 19. The thing with colour blind is, you will never know that you are colour blind unless you take the ishihara test. So for those who never took the test, you might be colour blind as well! lol