The voltage of the lamp is measured in Volts and the majority of lamps operate at 220 Volts. 

In some cases, lamps come with a transformer with a voltage of 12 Volts, 24 Volts, 42 Volts. 

To be sure about this, we check what is written on the old lamp we have removed.

Color temperature refers to how warm or cool the color is. The warmth of light is measured in Kelvin.

The lower the Kelvin rating, the more yellow the hues; the higher the rating, the more blue the hues.

Low color temperatures of 2700-3000K provide warm lighting, intermediate temperatures of 4000-5000K provide daylight, and high color temperatures of 5000-6500K provide cool lighting.