LEDs (light-emitting diode) are not replaced as are incandescent and florescent lightbulbs. Because of their long life (can be decades) and their low energy usage, they are less costly to operate and essentially pay for themselves.
Unfortunately the on off trigger/touch button does not keep its "on" setting when a timer turns off the electricity to the lamp. (I just checked with one of my light timers.) This same thing happens with most of the touch activated lamps I have used over the years.
This lamp provides a "cool white" light at every level of brightness. I would say around 5000-6000K. A notch or 2 down from bright daylight color. I am not an expert with the kelvin scale. I hope this helps. I love the lamp and for the price, it is fabulous!