Getting touch up paint for bikes can be a chore. If it was me I'd have a look at any of these places instead:
- the cosmetics section of a large department store, nail polish is available in a wide variety of colors.
- the shelf for touch up paint in a well-stocked car parts store. They usually have a nice selection of small bottles too.
- a toy store with a nice selection of plastic scale models. They usually also sell small pots of enamel in a wide variety of colors.
Or you can always ask at a bike store if they can get you some.