What a beautiful 1926 home — it has such great bones and character!

Some color combo

As for cleaning stucco.

Soft washing – A low-pressure wash with a mild detergent and water can remove grime, mildew, and staining without damaging the stucco.

Power washing (with care) – If the stucco is strong and in good condition, a professional can use gentle pressure washing. High pressure can cause damage, so this should be done carefully.

Or chemical washing.

Beautiful house. Yes clean the stucco. I love the current stucco color and would just go a couple shades darker for all the trim. The pink is not good!

Your siding seems to be olive green and the roof appears greenish in your pic. I'd pic a trim that's either a cream with a tinge of the olive green or a darker olive than the siding. That would unify the look. It's hard to say much about the stucco, because I expect it would lighten up a lot, if cleaned.