AFAIK, colour blindness ranges from barely an issue to an almost complete "grey-scale" style of insensitivity to colour. In general, the only safe design choice is ensuring that no decision-critical information is conveyed through colour alone.
Only if you want to catch 100% of the problems
I'm slightly colorblind and have had a hard time on the same level as the parent poster. Greyscale colorblindness (i.e. absence of color receptors) is extremely rare. PopCap does a colorblind safe mode (for zuma, peggle, etc), so did EA for Battlefield 3.
It might not be the best solution, but it's good enough for 80% of the colorblind.
There is a downside, a midway solution, although more realistic, reduces attention on the bigger problem, the rest of the colorblind population would be less catered to, but imho that already is the status quo and will be for the foreseeable future
The bad thing about this idea is that it wouldn't be reliable for the user's eye because of the variation of color representation across screens.
The good side is that it would be a correct representation of the accuracy of color recognition of the system screen-eye, which is much more relevant from a design perspective.
