Meaning of 渋 in Japanese

僕的にはもっと地味ってか渋い服が欲しいんですけどね。
For my tastes, I'd prefer plainer, or rather, more tasteful clothing.

まず目に飛び込んできたのは、大きなソファだ。渋い色の革張りで、座面も背もたれもゆったりしている。
The first thing that came to my attention was the large sofa. It was covered in sober coloured leather, the seat and the back both looked wide and comfortable.

彼はそんなものに金を使うのを渋った。
He grudged spending money on such a thing.

渋滞で遅れました。
I was delayed by a traffic jam.

彼は渋面を作り、教師の話を聞いていた。
He made a sour face, and listened to what his teacher had to say.