Dragoon:
For the coloring, I think the "age" of the tarantula is a big factor in it's coloring. Almost all the pics of young goliaths I've seen are like Tonka, dark brown with some reddish/pinkish hairs. Older, they seem to turn into a lighter but richer brown.
I can't wait till my Tonka gets to be that beautiful brown
As for the webbing, in my experience, they don't web much if at all. I wouldn't worry about the behavior you described, they probably don't produce as heavy silk as other species. (Some seem to produce multiple silk strands at once, others just one or two (completely personal observation)). Sometimes the webbing is so fine that we can't see it until it's gotten a few layers of it, my guess is that's what's going on with your T.
Mine just weaved a thin web mat when it's about to molt. My guess is that yours is probably doing the same
I must say, VERY nice specimen you have there!!!
Pixie