Every season RMK tend to release a few more permanent colors in addition to some limited edition shades. The limited edition shades start with the code "EX".
I like the way RMK names their polish shades, they are true to the names. If they say it's holographic soft pink, that's probably how it will largely turn out. Here's #101 holographic soft pink (from 2008 spring collection, limited edition) :
I'm not sure whether Holographic is just the word the Japanese cosmetic brand chose, I would say it's more properly described as 'flashing another color', but not quite duochrome. #101 is a medium geranium shimmery pink that flashes some green. The green flash is very subtle, barely picked up in my photo. However it does add an interesting touch to the color.
Here it is from another angle, where the green flash is far less obvious.
RMK nailpolishes are of high quality, they apply easily, does take a little longer to dry (but nothing a fast dry top coat won't fix).