I agree with some warmth in the Interlaps... I have the RG and it matches my G VS2 diamond.
I've come to the conclusion with the larger cz sizes, I may choose a Chinese White (warmer than RG) next time. It shows off warmth, beauty and sparkle, especially in larger sizes. That's just me tho.
If you go with Winfield's, ask them to send you the cz in both color ranges. They will refund you the cz you return when you place your order.