Gotta love those Classical Models...:)... They are purely the essence of GW´s Chaos Fluff, really cool Sculpt... Old School...
Your Version is neatly painted, like the combination of Purple and Green...:)... The Base should be more Nurglish, though, not simply sand... Maybe something coming out of the Ground and assisting the Warrior...?...:D...
However, Nicely painted Nurgleee... 8 Points...:)...
I feel the limitation of colours is actually a strength within this models colour scheme. Purple & green are a great combination to acheive the effect of evil & decomposition, however perhaps you selected shades that were too bright to acheive maximum contrast. Regardless I am impressed with the quality of this model & the base fits in quite well with the overall effect.