may be slow, but... well, he's just slow.
All parts of the model were painted separately. Firstly, I drybrushed all the flooring with Scorched Brown, then Graveyard Earth. This I did quite lightly, to keep the colour nice and dark. The 'flame' side then got another light drybrush of Blazing Orange, then Golden Yellow. The 'water' side got a light drybrush of Regal Blue, followed by Enchanted Blue. I didn't want to go for a full-on lighting effect on this model, because the light sources (the Elementals in the middle) are so big and central. A true light effect would obliterate any other painting. Plus it's tricky.
I'm not sure what the ornamental furniture behind the wizards should be called. Let's classify them as symbols. Anyway, each has to reflect the colour of flame and water, respectively. I did the eye with Blood Red, then highlighted up through Fiery Orange to Sunburst Yellow. I left the rest of the thing black (always a good colour to use if you can't think of another one!) highlighted with Codex Grey. The red ball was painted in Scab Red, then highlighted in the bottom half with Blood Red, Blazing Orange, then Sunburst Yellow. Of course, when I say I use these (or any other) colours when highlighting, I of course use lots of mixes in-between.
The water symbol was painted Chainmail, then given a wash of slightly watered-down black ink mixed with blue ink.
The bits and bobs lying around on the floor were painted in applicable colours for each side of the duel. Largely Dark Flesh and Vermin Brown for the flame side; and Shadow Grey and Space Wolf Grey for the water side.