
Disk pattern I made myself. The brush is only the repeating texture, not the colours. It will take after whatever colour is your current one, but will only be that colour unless you do the following operations:

TWO WAYS TO USE:
A) manually colouring the texture
1) light base colour and/or shape you want to apply the aura to
2) draw over the base on another layer and clip to layer (I personally don't clip to make a different edge effect I like)
3) lock transparency and colour both aura texture and base however you like
note: best if you want to choose where each specific colour is placed or include as many colours as you want
B) change to a colour changing brush
1) turn on "Randomize per stroke" tool property
2) pick a main and sub main colour you want for the aura
3) again, base/shape you want to apply the aura to
4) again, draw over the base on another layer. Switch between main and sub colours to change dominant colour as you draw. It'll blend while you're drawing.
note: you'd need to keep changing your main and/or sub-colours over time if you want to blend in more than two colours
You can change the pattern size and rotation in tool properties