1.202.2 Send methods

theme_colour ->initialise: name=name, derived_from=name|colour, summary=[string]*

Create a theme colour with the given name, derived from the given colour. The colour is added to @colours and @theme_colours and locked. Its colour<-rgba is @default until it is resolved. If a theme colour with this name exists, theme_colour<-lookup returns it after setting theme_colour->derived_from.

theme_colour ->derived_from: name|colour

Change the colour this colour is derived from. If it differs, the RGB value of all theme colours is reset, so they are resolved again on their next use. This does not redraw anything: use display_manager ->colours_changed after changing theme colours.

theme_colour ->unlink:

Remove the colour from @theme_colours and @colours.