Ego tank with CL4 clearimizer(?)

[dasgimp]

I have been Vaping for almost three years and started using a the CL4, and after the first cleaning and hot drying the CL4, the ejuice will darken before the tank is empty. My wife says it is because the liquid heats up. Has anyone else had this problem? The taste almost seems like it has gotten stronger, but that might be psychological. I thought about changing the wicks on the outside of the inner tube, but I am not sure if that is wise.