Alan .
If it's Acylic yes,
I had
. I've added a couple of drops of paint into the "water " using a small container. Mix it really well Don't try to add too much in one pour, as it will take ages to dry. Think the bottle says 1or 2 mm.
I have also painted the base first , where I had some reads and and wanted some depth , so a darker shade first, then added the water again in VERY thin layers , and kept it covered over while it dries. Mine took a couple of days to be fully dry, so allow plenty of time . HTH .
John .