Marakumo should have the fine dusted variegation of white on a pale green. The hue to the leaf is more pink than purple and does not persist for a long period of time after spring, although some leaves will hold some pink in the margins, but the majority become pale green with the white sand-dusted variegation. The leaf of Marakumo should be on the small side and the ones I have seen recently show a leaf that is much too large to be the right plant. Depending on the cutlure and sunlight, young plants can show little variegation or the variegation can be late to develop in the season. The pale green of the leaf can take a yellowish cast at certain time. What is interesting is that when the green veins come up in the leaf, there is the impression that the plant is actually a reticuated form, but not strong and it will fade as the season goes on--typical of seedling selections of reticulated parents.
So I suppose what you are looking for is a pale green leaf with darker green veins and some dusting or subdued white in the leaf.

mjh- Yea, I guess I was under the impression from some photos on the net that the leaf had more of a "reddish" cast with specks of white variegation... I guess I'm running out of space so I have to be more picky now... sad...