Hi Nancy and welcome. Where are you from? Your English is very good!

Ok... I was always told that blacks had the best coats... but I've seen so many blacks with soft coats that I dont think its true. From my own personal experience:
I've seen whites with horrible soft cotton coats.
I've seen whites with the most glorious, thick, coarse textured coats.
I've seen creams (most of them) with the thickest coat that you could lose a comb in.
I've seen blacks with lovely thick dense coats.
I've seen blacks with very soft thin coats.
MOST black coats tend to be curlier than whites.
Most browns I've seen tend to have thick and curly coats.
Most silvers I've seen have soft coats. They take much longer to mature and get an adult coat too.
Most apricots I've seen have soft but dense coats.
I havent seen enough reds but most of the ones I've seen have soft, fine coats.
I think it depends on the dog and the line... You can get good coats and bad coats in the same litter, but if you have a line of dogs with good coats you'll tend to have more of the good coats.
As for matting... it depends on the dog too. Pagan matted a lot. Montana went through phases where she mats a lot and then when she doesnt. I experiement with products, what works really well for a while will often stop working and I have to start over. With Pagan I kept her in oil (rich conditioning treatments) for her entire show career. I started that with Montana but found it was probably making things worse. I took her out of oil and found that she did best with a small amount of conditioner in the coat, rinsed out or simply sprayed onto her as I brushed.
Caring for pet coats is so much easier than show coats, but if you keep your dog in any length of coat at all it will need to be brushed at least once a week, probably twice if the coat is longer.