The Mason website has listings of all the colors available with a guide showing which ones are suitable for using in clay bodies and which ingredients to avoid in your clear glazes.
Why does this matter? Every clay body has ingredients in it that can react to a colorant. Sometimes that lovely pink fires green or the blue fires pink because of it. If your clear glaze has the wrong ingredient in it, it will change the colors or bleed them.
You can be reasonably safe if you stick with their guidelines, but safe is not always fun. I have tried dozens of other stains with great results. The trick is to test every single batch you blend in order to see what happens to the color with and without a glaze. Then you can decide whether to keep using it or not.
I had a pink stain that fired the most lovely pale green. I liked it and kept using it, but since I have the attention span of a gnat, I quickly forgot the pink was really green and ruined a pattern with the wrong color.
This is why I use the ones that look like the end product.
I would encourage you to buy an ounce or so of different colors and give them a try. Some are incredibly beautiful and are colors you cannot achieve by simply mixing two primaries.