Basically all you do is take the texture map your using now, load it into a paint program, and color the legs any color you want. If your character isn't going to be seen without the tunic, don't worry if you can't get the back and front exactly even -- just color them up to the point where the end of the leggings color will be hidden by the tunic. You can either use a single color for the legs (the easiest way), or -- what I do -- find a picture on the internet of someone wearing something close to what you want (to get a real fabric texture), save that picture to your computer, open it in the paint program, select a segment of the fabric color you want, copy it, paste it onto your figure's body texture somewhere in the area where you want it, then use the clone tool to spread the new color around to the area you want. Use a blending tool to smooth out the results. Believe me, I'm not really a texture map person myself. Included here is an example of what I'm talking about. The skin texture for this figure cam from a picture of a Halloween mask. I just copied and pasted segments that corresponded to the areas of the face I was working on and smeared the rest around to fill in the skin tone. Mike