can it be done without the sugar becoming lumpy?

Maybe mixing it with powdered food color?

A blender perhaps?

patticakesnc, I think pwd colors might work!

Any liquid or gel/paste food color will cause some of the sugar to dissolve, which will then cause lumps. Mixing with powdered food color would be the only option.

Perhaps you could put it in a food processor with the colored sanding sugar and pulse? It might work - conf. sugar is just ground granulated.

Put the sugar in a plastic bag add the coloured food dust and shake together, works like MAGIC!!!!

Yup...as PP's have mentioned, just mix with powdered colours or dusts...that's what one of my cake decorating books say to do. The result in the pic they have is the same consistency as plain PS.

HTH.

Color granulated sugar by placing in food storage bag and adding food color. Let it dry a bit..and put in food processor to make your own powdered sugar.

Powdered sugar can be successfully colored using gel/paste colors. Sift ps into a bowl, smear colorant onto (gloved) hand and work the ps by rubbing it between your hands...you'll be able to see the concentrated ps...simply continue working it into the rest...resift to remove any 'undesired' bits.

Thank you all for your ideas