Up to you but imo your pissing in the wind doing it just by trim pot position or plug colour etc. No 2 bikes fuel the same so using some elses trim settings is ball park at best and the trim pots are sufficiently sensitive that 1mm difference can throw things wildly out. Unless you get lucky you are likely to have worse fuelling than you started with.
The Co should also be slightly richer on the rear cylinder also as has less direct air flow and runs hotter than the front cylinder which will be reflected in plug appearance to an extent. Tuners like Gabro etc usually recommend .5 % richer on the rear. Most bike shops will set the trim for 1/2 hours labour and at least you then know it's right.