Sounds to me what you describe is a pretty standard pigment or tinted bottom lam & cutlap. If you glass and trim it properly it will need only minimal grinding at the tips/points and light feathering along the lap line just to knock off tips. It may get a bit powdery looking from sadning dust but will not affect the final color unless you grind it all the way through or your color is inconsistent. After you clean up, Use a plastic roller along the lap edge to CAREFULLY push the very edge of the lap into the foam ever so slightly … then walk around the board lightly baste the joint where the lap meets foam with 1" chip brush & lam resin to prevent bubbles in the joint whne you lam the deck. EDIT I just saw Balsa’s pics above showing exactly what I meant
I think what you are referring to is how the cloth looks after grinding/sanding down the high spots. This is SOP and nothing to worry about. The color is fine as long as you do not grind off too much cloth. To ease your concern, you can do this…After blowing off the areas really well, I use a small solvent brush and dry brush on a couple drops of styrene monomer over the sanded areas. It disolves any residual dust and satruates any cloth that became too “dry” when sanding. It will leave the surface perfectly prepared to be saturated with the deck lam and should fo the most part be unifmorm in color. You wil notice that on even the most well galssed vboards, you will see subtle shading variations on the nose and tail… this is becasue the cloth overlaps, and there is some extra resin…not a lot, maybe milimiters that we are talking aboutm that all contribute to making the color differ ever so slightly.
But that’s all part of the art form, and the beauty of a resin tinted board. And don’t worry, after a couple hundered resin tint lams you’ll start to get the hang of it.