spritecol is a definition of the color a sprite will appear in 2D mode, instead of the standard sky blue and hot pink, or another special color (like yellow for hard-coded enemies or white for the special sprites).
<normalcolornum> is the <colornum> of the 2dcol definition of your color for the standard sprite color as defined by <tilenum>. The same goes for <blockingcolornum>, except that this value is for when the sprite has the first bit of cstat set (1) (
[']+[B] keys in Mapster32), which is the blocking flag.
See also 2dcol.