I want to be able to make a FigureElement with a border set to the BaseColor, and the fill also set to BaseColor, but with an alpha value of 127.
Trouble is, can't seem to have both. Either I can have a base colour, or mix a colour (and add in alpha). I want the interface to look right regardless of user colour choices, so the background does need to make use of the BaseColor, but at the moment it can be too dark to read text on, etc.
Aiming for something that looks like this, and can vary with the user's choice of colour.