Patches of tall fescue or perennial ryegrass are currently much greener than Kentucky bluegrass (photos). Patches of these two grasses are prominent right now as the bluegrass is just starting to green up. Give it another week and the bluegrass will catch up with the tall fescue or ryegrass. No control is needed to remove the perennial ryegrass or tall fescue unless it is absolutely offensive to the homeowner in color, growth habit or texture. Digging them out or spraying with glyphosate or gluphosinate are the best ways to control tall fescue or perennial ryegrass.