Transition metal reaction colour changes?

I'm doing OCR A level Chemistry and all the textbooks and all the websites I've read contradict each other when it comes to the colour changes involved in transition metal precipitation and ligand substitution reactions. I wondered if anyone knew where I could find a list of "this-is-definitely-the-answer" colour changes for the reactions we need to know for OCR that you know is definitely definitely right??? Thank you!!!

state with a few examples in what context?

When you get asked something like "Ammonia is added to an aqueous solution of iron (III) sulphate, what colour change would you observe?" or "A solution containing iron 2+ ions gradually turned brown over time, why was this?" I want to know the correct colour changes for all the transition metal reactions we need to know for OCR Unit F325. I think they are Co 2+, Cu 2+, Fe 2+, Fe 3+, Cr 3+ and Al 3+ with NaOH, NH3 and HCl, but need clarification as the spec isn't very clear about it