Right then, Generally very colourful troops with red being predominant (the vast majority of troops wore something red, head band, cummerbund, cloth tied around the arm etc).
Red jacket and black trousers seemed to be common and separate units would have a 'uniform' of sorts, getting more uniform later in the war. Square unit badges on tunics for the Taipings and round for the Imperials.
Hair was grown long all over the head, as opposed to pigtails and shaven crowns, and tied up with any number of different types of cloths, coming more predominantly red as the wars progressed.
Pretty much anything would go but stick to the above very loose rules and you can't go wrong

There's obviously a lot more than that but I've only had chance for a cursory check.
cheers
James