Add site palette colors

[strarsis]

It would make sense to allow the easy addition of the colors (and gradients) registered by the theme.

[ajitbohra]

Can you elaborate more on this?

[ajitbohra]

Maybe related we are planning to add an option to quickly display site registered color palette instead of manually adding them.

[strarsis]

@ajitbohra: Yes, this is meant with this issue.
The site already got colors registered by the theme and these should be easily added to the ones shown on the frontend (by this block).