Step 1: What You Need
A PCB to dye
A Permanent Marker the colour you want to dye your PCB
Acetone (I use nail polish remover that has acetone as the main ingredient)
Step 2: LETS GO!
At this point it will look streaky and rough (like its just been colour in with a marker) but don't worry, the magic is yet to come!
Step 3: The Magic
This process will remove the streaky and rough marks made by the felt of the marker pen, leaving a beautiful smooth dyed finish ready for tinning & populating.
Step 4: Experiment With Colour
I would like to thank Kat from Sonodrome for all here help, and highly recommend her tutorial videos that can be found on the linked forum.