I use to race at Riders in Kalamazoo, MI in 91 on an indoor oval that they took 5 gallons of black paint and added sand to it and the painted the track. I think they said a gallon bucket to the 5 gallon pail. it worked real good with foam. was running green dots back then. of course like was said, it has to be real flat surface with no transistion difference between the concrete pours.