Hue-topia now displays the colour in a way which is more akin to the bulb itself, but the colour picker itself is the standard OSX colour picker. The tips below apply to Hue-topia and any other app which uses the standard colour picker.
When you've found a colour you like, save it as a favourite. Just drag and drop from the large swatch near the top (or from another colour well) to the little palette at the bottom. From now on you can just click on the little palette square to select the colour. Bonus tip - grab and drag that little handle just below the palette when it gets full.
2. drag and drop between colour wells
You don't even need to open the colour picker to copy a colour from one well to another. This works in any app that uses standard colour wells.
3. Other ways to choose colour
See the magnifying glass just below the toolbar? Click that to pick a colour from anywhere else on your screen.
If all of this isn't enough, you can add third-party plugins to the picker.
I bet there are some tricks that I've missed. Write them in the comments below.