There is no built-in way to import material data that I know of(though ArchiCAD does automatically create materials from imported models). The options would depend on what format the color swatches are in.
If they are in a human readable text format it would be possible to write a GDL part that could open it, parse the text and create material definitions.
The tedious approach would be to enter the RGB values manually. Assuming you can get them from the e-swatches. It is best to use RGB exclusively when setting colors in ArchiCAD as it doesn't understand other color spaces/pickers (HSB, CMYK) very well.
