If you have SCAL2 and the svg, there are a couple of different ways to do it. SCAL2 will import svg files at the dimensions they were made at, so you can save each color in it's own file, then import them into one scut file. Each import will go into its own SCAL layer.
An easier and faster way, is to create the layers in Inkscape. The quickest way is to select all of the pieces for a color, then use Control G (even if there is only one piece). Do this for each color. When this file is imported into SCAL2, each group will go into its own layer. The biggest drawback of this method is that files with Object/Group can't be used in SCAL1.
Another way to do this is to create real layers in Inkscape. Files made this way can be used in either version of SCAL as long as the pieces aren't overlapping. They layers can be moved in SCAL2 but not in SCAL1.
I have several posts on my blog about layers in Inkscape and SCAL2. Click on the tabs at the top of my blog. HTH