Knitoodle comes with a range of pre-set colours, allowing you great flexibility in creating your charts. In edit mode, you can change the name and description of each colour to match your requirements. When viewing a chart, tapping a square shows you the details of the colour and symbol in that square. A chart key is automatically generated when you export your chart as a PDF.
If you need more colours, get the Pro version and you can set up your own – add as many as you like!