My children ask me this question all the time and I struggle to answer it. Colour is and a important part of what I do; always has been even when I was a Florist. Part of my floristry training included the colour wheel and the theory of primary, tertiary, complimentary etc. Even then when picking flowers for floral displays it was the customers preference, you may have made a lovely tonal bouquet and the customer doesn't like it they love clashing colours.
Colours can lift moods and evoke memories, Red and Green - I bet you're thinking Christmas, Yellow and Blue - for me the beach, oranges and reds - Autumn leaves. Take these bracelets I made a few weeks ago.
The Red bracelet reminded me of the orient and it was inspired by Hong Kong, the Yellow bracelet with the green reminded me of Sherbet Lemons and the Blue bracelet with the gold also reminded me of things Oriental. To me every colour has possibility and can be combined with other to evoke many things. So I tell my children I like all colours I have no particular favourite.