We offer HID bulbs in 3 colors in our general inventory.  The colors you will find on our products page have been carefully selected by our staff as the best we can offer without compromising light output and color.  HID is rated in Kelvin, on the Kelvin scale the higher you go into the Indigo and Ultra Violet colors you loose light output.  White is the brightest color as far as light output is concerned.  In our Current inventory we offer 5000k Pure White which is our #1 recommended color for aftermarket and replacement HID kits and bulbs.  The reason suggest 5000k pure white over the other colors is that our 5000k white kits offer a brilliant white color that doesn't sacrifice one bit of light output yet is par with most stock HID equipped cars in color and brightness.  There are some that like to show off the blue color in their aftermarket HID conversion kits, for this application we offer a 6000k blue tint HID color.  Our 6000k blue is the best compromise for those who like the blue color and want to show off their bright lights without sacrificing too much of the light output.  Our third color offering is our 6000k Purple conversion kits.  The 6000k Purple is more of an exotic color and still has the brightness of the 6000k on the Kelvin scale yet it throws in a hint of purple mixed with the white color.  This is great for fog lights or off road accessory lights where output is not necessarily needed.