Altering or converting a sourdough recipe question - 2 questions

I made my first sourdough starter about 3 weeks ago. I've made exactly one loaf so far (only). I just keep refreshing weekly and putting it back in the fridge. 

Part of the reason I haven't really worked with it yet is that nearly every recipe is mostly white flour and I just don't bake with much white flour.  Does anyone have a good way of converting a sourdough starter to a mostly whole wheat or rye starter?

And... this start is a liquid, not a stiff starter. How do I convert that to a stiff starter if I wanted to do so?

whole-wheat or rye in the same proportions that you use for your white flour. Your starter will love it. To make a stiff starter, just use less water.