We have repaired the parging all around the bungalow wall. It is looking good but the repair is a different color to the original. We do not want to paint as this is an ongoing job over the years. Drylock was mentioned by a friend but we are told that this is thick and may cover the detail in the existing pattern. Something with a color and not too thick any ideas?

Drylock is a good option but there is no guarantee it will be the color you have right now. You could paint the entire wall withdrylock now and then touch up the repair spots with more Drylock as you go.