First of all this is lawn forum. There is probably a mulch forum but the Soils and Compost forum discusses mulch quite a bit. You can probably find the answer by reading there without even asking your question.

Personally I use a mulch made from a pest tree that grows north of San Antonio. I get mulch and the rancher gets his land cleared.

Gullit for the rubber, your talking about the Dupont Rubber Mulch? I was curious about this recently too, but found this article and went with wood. This article is harsh on every mulch except compost, just take fromm it what you will. I didnt read too much into it, but i did decide that rubber probably wasnt the right choice, i mean there is a reason that it (Bag Quote) prevents weeds for 15 years, due to it not breaking down.

Here is a link that might be useful: Harsh Mulch link.

I use the rubber mulch and love it, no more bringing home bags of new mulch every year. I have had it down for three years and it is still the original color, doesn't float or blow away, and less is needed to keep the weeds at bay. I only use mine to keep weeds away from my landscaping and for aesthetics. I have never smelled anything from it and it doesn't attract pests. I would definitely recommend it.

DO NOT use rubber mulch. especially if you ever would want to plant anything else there. the problem is, it wont break down so over time (especially if you are going to be planting new/different things in your beds periodically) the rubber will get incorporated into the soil and you will have chunks over rubber under the soil surface that will be impossible to totally remove. Go with some sort of wood based mulch (preferably one that has the smallest pieces - break down and provide nutrients to plants easier, and one you like the color of). Personally I do not like to dyed kinds either, just seems weird and unecessary to have some sort of dye in and around your plants.