My dad was colorblind, but there are very few people who are truely colorblind and see everything as a shade of gray. Colorblindness is more common in men, but the types of colorblindness are red/green and yellow/orange, IIRC. My dad's favorite color was yellow, but there is no telling about how it actually looked to him, since he saw yellow as a shade of green.
Now, I am a guy, and I don't have my 64 color box of Crayola's handy, but I would call that dress, from the pictures, a kind of seafoam green. It ain't teal, black, blue, surely not orange and it does not have "thin straps".