I went to the To the Redoubt show at Eastbourne at the weekend and bought about five packs of the Great War Miniatures figures: German jaegers and infantry and some French. They look very compatible with the Renegade figures and I wouldn't think they would look any different once painted.
I am currently working on my next unit of Guards infantry but this time painting them in the greyer uniforms of the early war period. I may have to go back and repaint my green-grey ones, grr!