I’ve not had good luck with the cocoa hull mulch. It does tend to mold quite a bit, especially if you have it in a fairly thick layer.
Something I saw just the other day was a mulch made of recycled car tires. It was actually quite fine (about penny size pieces) and the dark color looked great – yet I had to wonder if it’s truly good for the soil and plants. I would think it would absorb heat from the sun quickly and bake a plant in no time.
I love the look of deep, dark, rich soil.. so I’m not sure I’ll do much mulching this year unless I can find a suitable mulch to use.