The depot repaints definitely had a greener tinge, but I took this to be caused by the thin coat of blue paint (and possibly, no undercoat) allowing the green paint underneath to affect the shade.
I took a few photos of Toton Peaks in the depot repaint livery but it was difficult to include a works repainted blue loco in the same photograph for comparison, partly because there were, at that time, very few works repaint blue locos on the Nottingham division. When I saw 5021 next to a freshly works painted blue one I took the opportunity to photograph them (Crewe South - date in loft) and by being in the same photograph any difference in emulsion, colour sensitivity is ruled out. For some reason, it's displayed in a smaller size than I expected, though.
The mystery is where 5021 was repainted because all the other Sulzer 2s I saw in that style were Toton one, and generally of the later series.