Fig. 7. Comparisons of visual quality of tall fescue (TF), Kentucky bluegrass (KBG), and two hybrid bluegrasses (HBG1 and HBG2) within each irrigation treatment after a 52-d dry period (24 Aug to 14 Oct 2004; day of year 237 to 288). Ratings were on a scale from 1 (dead, brown turf) to 9 (optimum uniformity, density, and color) and 6 indicates acceptable quality for a home lawn. Means with same letters within each irrigation group were not significantly different (P < 0.05).

Image from Applied Turfgrass Science article:
Performance in the Transition Zone of Two Hybrid Bluegrasses Compared with Kentucky Bluegrass and Tall Fescue