Candy Apple Syrup Leftovers or ??/ I was thinking of making up the candy syrup and saving it to coat the apple later. I could take the candy syrup, and pour it on a buttered parchment paper, let it cool it bit and then blend a food color in it at that time, too.

I want to make little batches of different colors, not one huge batch of one color.  Is this workable, somewhow?
If you try to use a dry method (don't add water to the syrup when you heat it back up), you will likely get a very uneven heating and risk ruining the syrup. If you use a wet method (add water and let it evaporate), you will spend as much effort and time on the coating day as on making it from scratch, so your preparation would be superfluous. 

So, while in principle it could be made to work, it is easier and quicker to not do it. Just do it the normal way.