This show was great to highlight how confused women in particular are when it comes to 'their colours' and how to avoid the safe option of 'black'.
There are different ways of grouping colours togther in palettes or shades and the three Trinny & Susannah allude to are a good way of simplifying things. I am founder of a Personal Styling business 'Style Our Souls' and we run lots of colour sessions for women (and men for that matter!).
We find that 'having your colours done' dramatically changes the way you shop and put your wardrobe together. The main thing is it saves you money in the long run, because you avoid those fashion disasters! We identify if you're 'cool' or 'warm' and then narrow your palette even further to show you if you need bright or soft and light or deep.
I would highly recommend seeking out a professional colour session as a good starting point to revamping yourself or just tweaking your style simply, it will make getting dressed in a morning much easier!!