The label could be this one http://glassgallery.yobunny.org.uk/displayimage.php?album=102&pos=87
which is a generic Murano label, that is a label that can't be attributed to a single company. If it were Barbini or Fratelli Toso it would at some point had one their labels on.
Are certain colours worth more than others? Perhaps, but colours are so personal. It's not a piece that you could attribute to a specific designer, imho, as many companies produced very similar pieces.
You could check completed sales on eBay for this style and colour. to get a sense of rarity and value on eBay. Also have a look at soem of the Internet sites that sell Murano to see if they have a similar piece. The prices will be much higher there.
I'll add that I don't intend to sound negative about the piece. I've got a few very similar pieces that I really enjoy. Part of the enjoyment is having a production piece of a functional object that has some real artistic appeal.