Sometimes the best thing you can do is sit at your computer and play with Photoshop. This original photo was actually taken last year at our Jubilee cricket match.
Doing a colour palette actually teaches you a lot about the importance of layers. If I were to put each of those colour boxes straight onto a grey background, then they all come out washed out. If I use white, it is very difficult to "paint" over that colour. Black is the same.
However, if you use a new layer for each of the squares, then the colours come out very true. That's my thing I've learnt for the day!