White was the replacement clicky switch for blue – neved used one. I find that my Fukka white simplified keyboard is less tactile, but therefore significantly smoother than my blue ALPS keyboard. All but the latest greens are linear switches. Pretty much every other colour is tactile only – the only clicky colours are blue, white, and the most recent greens.
It's not just colour and tactile vs click vs liner – many colours are shared between complicated (self-contained microswitch block, in long and short switchplate varieties), and the four varieties of simplified (open microswitch), namely Type I ("Fukka"), II ("XM"), III, and IV, the last one being a I/II hybrid that's better than Type II (less balky) but still a lot stiffer than Type I. I feel sure that old long switchplate tactile complicated switches are a lot smoother and softer than the short switchplate black tactile complicated switches in the Dell AT10* family that are spongey and frictioney. Those are more like Cherry clears in feel, but poorly tactile.
The only way to be sure what you've got is to open up a switch, but the simplified ones are a pain to reassemble -- with type IV at least, the two metal parts of the microswitch are held in place by grooves in the upper housing of the switch and it's really hard getting them to slide back into those grooves! Complicated switches have a plastic block that holds the microswitch components together even when you remove the upper housing, slider, return spring and tactile/click leaf. The length of that plastic containing block alone (the switchplate) is theorised to have a noticeable affect on how smooth the switch feels.
All this is largely undocumented. No rationales, no specifications, no schematics. I do wonder whether Types I to IV are even numbered in order of introduction by ALPS, as I have a huge PC/XT/AT switchable keyboard (no date) with Type IV simplifieds, long before I thought they'd been introduced! I have another, similar keyboard, but PC/AT only, that has blue complicated switches.
