Mixing base colours when none available help

[Jaiaceae]

I used to work with a colourist and he used a calculator to work out exactly how much of bases to mix together to create one of there is none available. Obviously these are more tricky ones such as making a 5 when there is a 3 and 7 only. Or creating an 8 if there is only a 6 and 10 etc.. I hope someone can help with this as this would be a neat trick to know.

 

[AcidPerm]

An old but very useful thread on this exact topic.
@adamlea87 explains it really well. Enjoy reading!

http://www.salongeek.com/threads/colour-mixing.272374/#post-2291326