| CLASS | (B-V) | (B-V) | REFERENCE |
| min | max | ||
| Stars | -0.2 | +1.8 | Esa (1997) |
| WDs | -0.3 | +1.6 | Bergeron et al. (1995) |
| CVs | +0.2 | +2.0 | Henden & Honeycutt (1995) |
| Galaxies | +0.2 | +1.6 | Prugniel & Heraudeau (1998) |
| Clusters | +1.0 | +1.5 | Chieregato (2005) |
| AGN | -0.6 | +1.6 | Veron-Cetty & Veron (2003) |