for the next 3.3 alpha i have added:
IconColourOverride.Default fg=XXX
IconColourOverride.Disabled fg=XXX
IconColourOverride.Highlight fg=XXX
IconColourOverride.Highlight is used for the edit save button on mouse over, and IconColourOverride.Disabled is used on the back/forward buttons in the header
Its applied to most icons, except a few such as the rss podcast feed icon. However I am not sure how well this will work in practice as I can imagine you might not want it applied to some icons i have enabled this, so I will need feedback on icons it shouldnt be applied to