The new Yok springs, the softer three, black(YS-1460L), blue(YS-14575L) and yellow(YS-1455L) seems to be the same as the Rayspeed green, blue & yellow. Same size wire, same # of coils. Look at the part #, YS-1460L, 1460 means 1.4mm wire with 6.0 coils. Although the other three are different.
The HPI blue is also 1.4mm wire with 6.0 coils(OK, slightly shorter & maybe different grade of material). Chris Grainger says it is very close to Rayspeed green(I agree), though some people think HPI blue is similar to Rayspeed blue or yellow.(not start an argue here)