Hi,
What do you mean it is not working/working wrong? I am not sure I understand the issue you are having.
Kelvin temp is working only with numeric input in the respective field. You cannot pick a color for Kelvin temp. The displayed color next to the kelvin temperature is the resulting color, after settings the Kelvin value.
For the other color slot, you can have any input you want. If you want the color field to be exactly of, say, 4000 kelvin, you need to use the Kelvin temperature slider in Corona Color Picker.
See attached.