Kick out flashing where the siding meets the shoulder of the chimney. You can't tell from the angle but there is a 3/8" gap between the end of the siding board and the flashing. Everything in the pic will be white when final painted.
I ran out of white polyurethane and had to use tan and the tan flashing was made from scrap .
The slot for the kickout flashing has 2 coats of primer/paint in it and will be caulked, but it should never see any water anyway.