Add support to specify colors using RGB ?

[edi9999]

FZF seems to be handling this :

https://github.com/junegunn/fzf

--color 'fg:#bbccdd,fg+:#ddeeff,bg:#334455,preview-bg:#223344,border:#778899'

Currently, icdiff only accepts a small subset of all possible colors.

It could also be done with ANSI codes but I would find it even cooler to simply use RGB which is easier to parse for a human.

[edi9999]

The code for the handling of ansi codes in FZF (in golang) is here :

https://github.com/junegunn/fzf/blob/261d3d3340a9afa9925ec693a47ebe632d6870cb/src/ansi.go

Maybe one could start from this instead which is in Python :

https://github.com/cbouy/asciipainter/blob/master/asciipainter.py#L33