Include a reference for Colorblind People

[behkod]

I see the colorblindness is covered in the guidelines, but not everyone is nerd & sympathetic enough to research thoroughly into every topic that (s)he isn't suffering from.

I think its really good idea to suggest colorblind-safe color pallets to be used in frames. Or at least provide links to authentic sources:

Here are two I prefer most:

• ColorBlind-Safe Online Color-Scheme Loader
• Colorblind Safe Color Schemes by NCEAS SC Recource Corner: .pdf

[tmm]

PR welcome!