The phrase "a white visor" is correct and usable in written English.
You can use it to describe a type of headwear that is typically worn in sunny conditions, often associated with sports or outdoor activities.
Example: "She wore a white visor to shield her eyes from the sun while playing tennis."
Alternatives: "a white cap" or "a white sunshade".
Williams, smart in a white visor, led the way on to the court, which helped to dispel, at least in part, the greyness of a drab afternoon.
In line for the ferry from Manhattan to Rockaway was a blond woman wearing dark glasses, white shorts, a white shirt, white mules, and a white visor.
On another day bird-watchers were out in force, and I asked a purposeful-looking, binocular-toting woman in a white visor and tennis shoes what she had seen.
"This isn't just croquet, it's Six Wicket Croquet, and this is an invitational tournament," a woman in a white visor with the words "Bad Hair Day" on it informs me.
By Mary Norris In line for the ferry from Manhattan to Rockaway was a blond woman wearing dark glasses, white shorts, a white shirt, white mules, and a white visor.
Others, however, were taken with another of her stylish on-court displays: her hairdo, which featured a tightly woven central braid that ran across the crown of her blond head into a long fishtail ponytail that poked out of the back of a white visor.
Wills, who never appeared for a match without her signature stark white visor, won 31 Grand Slam titles in her 15 years of competition.
The object of their curiosity, Ai Sugiyama, took to the court in a Granny Smith apple-green skirt, white visor and modest earrings.
One day at the Masters this year, for example, Luke Donald wore a pink shirt, Kelly green pants and white visor.
His blue eyes were piercing beneath a white sun visor.
The woman ambled near the water, with a white sun visor on and a Royal Caribbean fanny pack slung over one shoulder.
