Sweaty and Exhausted

I've looked many times at the line-art or sketch version of this excellent painting. I have, in my own crude ways, moved some of my pieces from line-art to colored images and with doing the latter -which often demands more depicted 'completeness'- I have run into 'struggles' --with my works getting muddied up compared to the freshness of sketches. Now, I don't feel you've run into this painting looking particularly over-worked (a common danger of wishing to 'add more' to the original rendition).
I'm guessing that here it is a question of mixed consistencies, both in the quagmire rendered and rendering techniques. The sharp-edged spatter on much of her tee and skin suggests that, at some point in her long visit, very watery and thin mud splashed on her whereas the very thick consistency in general body of the mire depicted here would not be likely to spatter; the evidence of her now-plowing through thick mire would be largely smoothly 'smeary'-looking with much fewer hard-edged islands of splat and other hard edges of splatter. If you wish to leave some of those splats... visual assets as 'beauty marks' testifying to her earlier struggles in looser parts of the morass, 'balance' them off by adding more 'smear style' in areas where her body is presently close to and meets with the surface. Also, it's possible that much of the line work in her wake might be replaced with more 'painterly', 'smeary', largely darker (for shadowing) color rendering of the viscous roils the present consistencies would display... I don't think that it's going to take much! Don't overdo this and make it look like an oil slick.
You're much braver than I am about doing color! ... I'm just a sketcher and 'drawrer'. This already is a very fine painting! She's sinking nicely.