I have done a couple of FBCT and they came out fine, but they all were pictures that were outlined in black. I am making a cake for a baby shower and wanted to do a few FBCT's, but the pictures that I want to use are not outlined in black. Can I just use something like the recipe for the FBCT and tint, outline, and fill with all the same icing and same color? Does the outline icing need to be thicker than what I fill in with? Thanks in advance for any help!!

You can use whatever colors you like, black is just usually recommended because it gives you the most contrast so the best detail. I'm sure I've seen white, but if you don't want a line between colors you really don't need to have them. And since the outline is just that, not a dam like in royal icing work or color flow, it can be the same consistency as the rest of the BCT.

I've used other colors besides black to outline my transfers, just depends on the look you are going for. I always use the some consistency for all of the transfer.