Beautiful chick . I think Polish (and silkies) are at high risk from predators regardless of color. They do not see as well with the big crests, as other breeds do.
Hmm that's odd from the wing growth I'd say it's most likely a little roo but from tail growth I'd say it's most likely a little pullet... I'd keep an eye on its tail growth over the next few days. If it's tail grows a little more and it starts trying to hold it's tail up as high as it can he's definitely a roo.
Usually there about three to four days old if you get them at a feed Store if you get them from a hatchery there probably about two to three days old when you got them