I need to make a number for the top of a cake and after I melted the candy I added the red coloring and it instantly made the candy hard before I had a chance to pour it into the molds.Any idea what I did wrong or any tips...

I'm pretty sure that you used regular food coloring. Paste colors have water in them and water causes candy to seize.

To fix this try adding a little shortening to your candy, it should smooth it out.

In the future either buy your candy already colored, buy special oil based colors or if you must use regular colors for some reason add the shortening with the coloring.

Thanks for the advice,I will try that...