I will keep an eye out for a bit of Monart in this colour for you.

(I'm not too sure there isn't a little Vasart trumpet posy with mica in it, somewhere nearby for ~£5. It's been gathering dust there for years.)
It's
almost like a Rothko painting in it's intensity and the interest it inspires.

I'm sure it must have something to do with brains not being able to quite decide what shade it truly is. A bit of "cognitive dissonance" can be really quite enjoyable.