You address the run off issue properly with a french drain for instance which can be buried or you can do a false stream bed sort of what you are doing. But the best is to find out why you are having the issue . It could be your gutters are plugged or the down spout is in the wrong place so have those checked first. Layers of rocks are abetter choice than a tarp and one layer of rockes . The different layers creat a better handling of the water, you can google french drains and get good advice on how to install them.As for the color that really is just the color rocks you chose .

YOu have to explain exactly what you mean by "a runoff problem." All rain runs off somewhere, but it's not a problem unless it accumulates where not wanted, or if it causes damage.

It will not work to create the gravel bed as you have. You cannot heap any soil or gravel onto a fence without destroying the covered portion ... in not all that much time. Whatever you're trying to do, you're going about it the hard way. Back up and carefully explain the problem in detail. Add pictures that corroborate your explanation. If you mention something, SHOW it.