This is a really cheap, and crafty way of making your keyboard your own style. With Japanese Washi tape. I bought mine from Lebox botique on Etsy, because you can buy it by the foot. Its also very cheap. This is the link...
Step 1: Materials
2. Washi Tape
3. Cardboard to cut on
4. And of course your keyboard
Step 2: First Attempt
I decided to then do my old macbook pro that is all silver.
Step 3: How to Apply
Is to place your tape straight on the keys, keeping it taut by rolling some extra on the keys next to it.
Then take your exacto knife and cut the tape the exact size of the key. I used the detail blade that I got with my knife.
A side note I might add, the tape is much like painters tape so you can pull it off and re-apply if you don't get it on straight the first time.
Step 4: Patience!
This is what I ended up with, and I am quite happy with it.