you can mix a small amount of acrylic hobby paint with the white spackle to make it balsa colored..lift the different lightweight spackles to compare weight..I do believe the model magic is slightly better than the spackle but much much more expensive..If you only need a smalll can I might be tempted to use the hobby stuff.

I have had issues with the fillers when using sig stix it and cloth coverings...if you need to reposition something I have actually pulled the spackle up before..and they don't like a lot of heat off of an iron either...