Not only can you use the straight white-on-black smoke shots I took yesterday, but with a bit of work in Photoshop, you can create some other-worldly abstracts.
First of all, take your white on black image and Invert (CTL-I). This gives you a brown/grey pattern on white. Make a new Adjustment layer and choose Hue/Saturation. Click OK, and at the next dialogue box, tick the “colorize” box at the bottom RHS. You can then move the hue and saturation sliders about to give your smoke the colour of your choice.
If you want to mirror or duplicate some layers, use the Multiply blending mode to make each show through the one below. Flip, clone, rotate, have some fun!