A red study, but on the brownish end of the red spectrum.
The palette: Rembrandt Transparent Oxide Red and Transparent Oxide Brown. The addition of white increased opacity where necessary; there is also a tiny bit of black in this but used with great care because black and cats do not seem to go together.
I have discovered that leaving out the white until as late as possible is the best solution; once added in, it seems to spread everywhere and then the darks cease to be dark enough so then you reach for the black, then you get mud, then there are tears before bedtime. This is the trouble with cats.
At the start, the plan was to use orange, but in the event this underpainting was left to dry and I switched to the red palette: