I don't know what I'm doing wrong (LWI). I do the first color, then I do another color but the contrast is not that different. Maybe I'm using colors that are too similar. Can't figure it out.

Sometimes I put the first color (for example, orange) in a cup or two of water in the bottom of my container, then add my fabric. After that, I pour a different color (e.g., purple) on top. I generally add enough liquid to almost submerge the fabric without soda ash, so it's pretty much covered with soda ash when I'm done. No stirring AT ALL if you want sharp differences. The soda ash miraculously penetrates the whole thing with no stirring at all. If there is any fabric sticking out, I try to pour the dye and then the soda ash right over it so nothing remains dry.
Another way to do it is to pour one color over on half of the surface area (roughly speaking) and another color on the other half.
If you want really, really well-defined color contrasts, you can use the first method, adding some dye to the container before the fabric, but put some soda ash in before the fabric as well. That encourages the dye to strike immediately (especially if you use a fast-striking color such as fuchsia, red MX-8B).
For maximizing color patterns, be careful to cram the fabric into its container quite tightly. If the fabric is too loose, then all the dye floats around and hits every bit of the fabric rather evenly. Use a smaller container if necessary. Don't try this in a soft-sided container such as a plastic bag. You can also add salt to increase the crystall patterns; try one teaspoon of salt per cup of total water volume, but don't add salt to the dye until after you have dissolved it, since salt makes dye less soluble.
Ann Johnston does "color parfaits", in which she puts one piece of fabric in the container, then pours over some dye, then adds another piece of fabric, pours on another color of dye, then a third piece of fabric, then pours on a third color and all of the soda ash. This makes related color schemes that are ideal for using together in a quilt. I strongly recommend you read
Color By Accident. Her methods are a little different from mine.
Paula, will those applicator bottles from Dharma work with the elmer's? Will they still resist to white?
I think that you need this sort of applicator bottle, for sure, but I do not know for sure whether the Elmer's Washable Blue School Gel will work in fine lines. There is a possibility that it might not penetrate the fabric well enough, and dye might come in from the back side of the fabric. It depends on the thickness of the fabric. If the glue gel does not work, you'll need to use a different resist product with a fine tip applicator bottle. There are many different water-soluble products, but people still use gutta and wax, as well, because thre's nothing else quite like them. If you decide to try wax, you'll want a tjanting. You need an electric skillet or some other way to melt wax if you use beeswax and or paraffin (the traditional batik "crackle" effect will go over very well with the yoga themes), but if you use soy wax I think you can manage with a double boiler. I have not yet tried soy wax, but I just acquired some on Judy's recommendation.
Paula