So while my yellows were mainly just reds, it turns out my reds need a suspicious amount of yellow and blue.
My genuine colourblindness cannot possibly be at fault.
A front shot of a charming bald lady (definitely not a bug), mainly still zenithal primer but with a fancy frock that may or may not read as red.A side view of the same lady (not a bug) showing the extent of the yellow in the highlights, the blue in the shadows, against a red midtone.The flowing train of the rear of the model hopefully distracts from the absolute carnage of my painting desk that I’m only now realising is clearly visible in the background of the shot, strewn with paint pots, tubes and brushes.