I just noticed that in tied notes, only the first note honours the “Colour” setting, the tied ones remain black. Accidentals aren’t coloured either. I suppose that’s not what is intended?
By the way: Is it possible (or legal) to have a slur stop at the first note in a sequence of tied notes (instead of the last one)? Or is there another way to make the slurs look nicer than in the example above?
I think your example slurs look about as good as they get for these figures. The modern rule is that a slur should always include any tied values. Classical composers such as Mozart and Beethoven often broke this rule (presumably because it wasn’t a rule yet). So as an editor I sometimes carefully break the rule if it can reduce clutter significantly. Unfortunately, in this example, slurring only to the accented note won’t help with clarity because of the triplet and the second voice.
Good idea, I checked: No, the color attribute is already set to the changed color when I select the tie, and even setting it again doesn’t change anything.