Possible to control both RGBW White AND RGB White?

[Burrington]

I have RGBW Strips on my Eaves (WS2814, warm white). I have xlights set for R==G==B->W. The warm white looks great while only the house is lit, but normal RGB Cool White looks better for the Christmas Display. I can get cool white by setting a custom white colour to 254,255,255. But that means changing hundreds of effects in my light shows. Is there any way to leave xlights set to "RGB Only", but still control the W channel in the few cases I want them to be Warm White?