But the con range changes as you gain levels. Orange can be as high as three two levels above you, yellow can be as low as four levels below you in the higher levels. By observing how the mobs change con as you level, you can decide which mobs are best for you to hunt in order to gain the most experience over time.
Leveling tip #3
Never solo hunt mobs for per kill experience. Always look at the experience you gain OVER TIME.