Hi DM1,
i can confirm Djuri‘s experience. Double checked rasterization of the layer below. Added a lens filter, turned up density and opacity - everything goes orange. Changed the color - nothing happened.
Not sure about density and opacity, I’m on the German version, but should be something like that.
AP2 doesn‘t even seem to accept my color input sometimes and resets it to blank. That doesn‘t have a pattern I can find though. But no matter whether the color field shows nothing, blue, green, red, pink - it always goes orange, color does not change.
edit: specs are: iPad Pro 9,7 - iOS 15.6.1 - Apple Pen 1 - Affinity Photo 2.0.1.307