Kelvin temps won't make the lights brighter. In fact, you lose lumens as you increase temperature. Make sure everything is aimed correctly. I have no qualms about my HIDs.
08 X Sport/Ent -- Sterling Gray/Ebony
03 X Touring/RES -- Taffeta White/Saddle
02 Honda S2000 -- Berlina Black/Black
99 Acura RL -- Naples Gold Metallic/Parchment
12 Toyota Avalon Limited
12 Toyota Highlander V6