I'm trying to find some touch-up paint to cover some scratches
Want an exact match?
It's the same paint the manufacturers use. Anything else is just "close".
Note: If you're repainting the entire bike, there are much cheaper alternatives, such as Plastikote, Duplicolor, or Krylon Fusion.
For touch-ups there is a cheaper 'good enough', if less permanent, alternative. This is recommended for scratches and cracks only. It won't work on larger areas and probably won't last forever even on smaller ones. Take the body part in question to Home Depot, or somewhere else that has computerized color-matching, and have them match the color. A quart of glossy paint should run about ~$10.
Use a small art brush to apply it. Since it's latex, it isn't hard and can be scratched off easily, so a large exterior area would not work too well. It might not be as permanent as proper touch-up paint, but the price is much better. And even if it starts to look bad in a year or so, you'll have 99.99% of the quart to reapply.