Both Diva and Ruby Woo look beautiful on you. I love both sets of pictures you posted, you look great!
I own Diva, Dubonnet and Russian Red and I'd like to pick up a Ruby Woo as well. If you decide you don't like the bright red lip, you can always put on a darker lip liner, then Ruby Woo, then a dark gloss. Or combine Diva and RW.
Russian Red has a more blue tone to it and Dubonnet is a little lighter than Diva with slightly different tone, I believe. Dubonnet really reminds me of the singer Regina Spektor.
You'll get used to a brighter lip. I was always a very light nude l/s kind of girl and then I tried Russian Red and fell in love. Now, I wear red lips every single day. I mean, you look beautiful in it, so why not?!