Here is a very simple way to make a gradient that is pure from a chart or a picture that you particularly like the colours of.
The advantage of doing it this way is that you don't get loads and loads of nodes that aren't necessarily needed, and the colours you pick will be cleaner looking.
1. Download and save the image or chart into your Ultra Fractal Image folder; (you will find this inside your documents and ultra Fractal folder.);
2. then make a new fractal using Pixel formula and the Image.ucl on the outside tab (both in Standard);
3. Open the little folder icon in Image and choose the chart you have just saved into there. Centre it an