Has the "Show Colors" palette of Mail moved out of reach in Mojave?

Before Mojave (as all ancient tales now begin) I used to position and click the Show Colours palette of macOS Mail by finding a reference to it through a scripting action.

The applicationProcess reference returned for Mail by System Events scripts no longer seems to provide a reference to the color selection window, and I while I can use KM to select the Mail > Format > (Show|Hide) Colours menu Item, I don't seem to be able to reference the window/palette itself with KM conditions like "Window contains title".

Has anybody else found a way of positioning and clicking on the Show Colors window in Mojave ?

(I regularly use four text colours in Mail, and I like to use the keyboard to click on one of 4 custom-color-square positions without taking eyes off the text, using one base position, relative to the top left of the Show Colours window, and three multiples of a constant x offset)