Is there only 1, or is abox of so many for 7.99?

The price is for one.

Does this pill box exist in any other color, specifically yellow or blue

Unfortunately, this specific item only comes in one color. The closest planner to it in another color is our blue Apex Pocket Med Pack - 2 Pack which can be found here: https://carex.com/products/apex-pocket-med-pack-2-pack