itip-formatter: Colorize meeting summary with the event color
Evolution does not show the COLOR of iCalendar invitations. I propose rendering the title’s background of the event in the iTIP formatter using the COLOR from the invitation, when present, and render the title foreground in black or white, depending on which of black/white has higher contrast to the background.
Next are two iCalendar invitations containing COLOR. The HTML part of the invitation implements this idea and shows the title’s text in contrasting color.