Add colour input field

[varkor]

It would be convenient to be able to specify colours using an input field, e.g. HTML hex format. Currently, the only precise way to input colours is to import a macro file, which isn't always convenient.

[ccatrett]

I am a bit confused. There is already support for changing the colors of text as well as parts of diagrams, e.g., arrows.
What other parts of the UI were you hoping to give the ability to customize?

[varkor]

There is currently only a colour wheel for specifying diagram colours, rather than any text input, e.g. for inputting hex codes.