I did something similar in the kitchen at the back of a worktop (I actually chipped a big chunk off with a drill), and being an artist by profession, I was able to touch in the colour using acrylic paints (the plasticky type you get in tubes from artists shops). I just put a blob of white, a blob of brown and a blob of black on a piece of card, and mixed up a few similar looking shades, and dabbed them on very thinly using a small brush, imitating the pattern and colour of the worktop. You can't see it at all now, however it's right at the back of the worktop, which doesn't get any heavy use, and also isn't in an area with strong light.
Our worktops are are of a matt effect laminated mdf. I'd imagine it'd stand out like a sore thumb on a glossy worktop.