Described is dynamic control of the temperature of the envelope of an HID lamp in order to stabilize the output color temperature of the lamp. As the lamp power is changed, or environmental factors alter the lamp envelope temperature, the system senses these changes and adjusts the lamp cooling systems so as to move the lamp envelope temperature back to the desired point.

Described is dynamic control of the temperature of the envelope of an HID lamp in order to stabilize the output color temperature of the lamp. As the lamp power is changed, or environmental factors alter the lamp envelope temperature, the system senses these changes and adjusts the lamp cooling systems so as to move the lamp envelope temperature back to the desired point.