Adding CSS4s RebeccaPurple as a possible value for the /color command

[ChainsLunatic]

The subject says it all; I want to propose adding the RebeccaPurple color to be usable with the /color command.

Why?
- It's (probably) easy to add
- It's an easy to remember color name
- It's part of the official CSS4 color list
- And the most important part that led me to proposing it: the story behind it really touches heart.