I've used a whole jar of paste and it still isn't red. Any tips out there? Also, the same with black.
All you can do is add color and wait. The color deepens as it sits.
But I'm lazy....if I need red or black icing I buy it. I just HATE coloring icing, and dark colors are the WORST.....
If I need a whole cake red or black, I use my airbrush.
You need to wait at least 2 hours, especially if you are using Wilton colors. Overnight is even better.
i really suggest getting americolor super red. it works very well and it won't change the flavor.
I've found that when making red and black, trial and error is the best teacher.
On the red, you have to get the color right above the color pink, to this color that isn't pink but definitely not red. To know if you have it the right color, smear a spatula full of icing on the back of a white plate (I like corning, because mine are white). Wait an hour or more and check the color. You will be surprised how red your sort-of-red icing turns.
The same holds true for black, take it to a color just above grey to a dark grey and test it.
Testing is the only way to not only save on coloring but not make your icing taste nasty. By the way, the only red I use is Wilton no-taste red. All the other reds I've tried give an awful flavor to the icing.
Try adding pink paste color and than red. Also, i found with black it helps to add brown paste color than black.