For a box mag just run a 5:1 ratio. Get a big bag or jar and dump them in, mix and enjoy.
Since .25's are the current heaviest tracers, I just run .25's on everything I own and make it work. I typically run 2:1 or 3:1 though. For loading black and whites for daytime tracer effect, I'm lazy so it's 1:1 for an m249 big box mag.
For the Muskoka 24hr milsim, when it got dark, I just swapped to 100% tracers on my WE PDW. No, I did not modify my tracer unit to allow for a brighter muzzle flash.
When the temps got low and it started over hopping, I just utilized the magic bullet effect around trees and bushes.