The background color of the little box in the target window indicates a level range. Green = 1-30 (?) Blue = 1-50 Yellow = 50-100 Orange = 100-150 Red = 150-200 Purple = 200-250 The number next to the star indicates a more precise range. 1* Green, for example, would be level 1-10. 2* Green, level 10-20. 3* Green, 20-30. 3* Yellow, 70-80. 2* Red, 160-170. One black star on a colored background is a named mob. Two black stars on a colored background is a boss.