Black is bad because it absorbs the light. The media layer should be greenish or blueish and should be sandwiched between a translucent layer at the the bottom and a silver (for blue CDs) or gold (for green CDs) reflective layer adjacent the top. The coloured compound at the top adds to rigidity and allows for decoration. The more expensive disks have an extra compund film on the bottom. This slightly reduces transmissivity but protects the surface that much longer.

The long and short of it is that Green/Blue makes no difference. If your original games also take a long time to load, then your laser needs calibration. If it's your vVerbatims, then look to a weak burner if there is such a thing because either it copies and checksums or it doesn't. Can't help more at this stage. Or Clean the laser lens with a flail CD.