"Grey sky! Gray hair! The second you see gray hair it raises the question , just like when you cut bangs ..to keep or not to keep," she wrote alongside multiple photos of herself on the beach.
"Thank goodness both are just a personal preference or a fun change of pace," she wrote.
Christie Brinkley debuted her new gray hair while happily posing on the beach. (Christie Brinkley Instagram)
CHRISTIE BRINKLEY TALKS AGE-DEFYING LOOKS AND DISHES ON MEMORABLE 'SPORTS ILLUSTRATED' PHOTOSHOOTS
Brinkley acknowledged her son Jack Cook thought positively of the change writing, "My son thinks it looks cool, but I think I may want to wait till it’s more like the silver whitecaps than the grey wave itself! The verdict is still out," she wrote.
Brinkley also has two daughters, Alexa Ray Joel with ex-husband Billy Joel and Sailor Brinkley Cook with ex-husband Peter Cook.
Christie Brinkley shared that her son Jack, 27, likes the gray hair on her. (Myrna M. Suarez)
From left to right, Alexa Ray Joel, Christie Brinkley and Sailor Lee Brinkley-Cook attend the Sports Illustrated Swimsuit 2017 launch event. (ANGELA WEISS/AFP via Getty Images)
The "Sports Illustrated" model was met with a plethora of comments telling her to keep her infamous blonde locks, with one user writing, "I've always loved your blonde hair. I would keep it. It goes with your youthful face & personality." While another person more pointedly commented, "It may be ‘cool’ but not as flattering. Just my honest opinion."
Others in the comment section were more encouraging of Brinkley's change, with one person saying, "I’m gonna go against most of the comments here! The gray at the roots is gorgeous and the various strands already show definition! Gray with your beautiful face would be stunning!"
Someone else offered kind words commenting, "You could have a paper bag on your head and still be the most beautiful one in the room. You’re also the one with the most beautiful heart!"
Age has not deterred Brinkley from flaunting what she has got, often posting photographs in a bathing suit and being lauded with compliments in the comments section of her social media.
Christie Brinkley laughed in a photo that showed off her gray roots. (Christie Brinkley Instagram)
Just last month, the model showed off her elongated legs and slim frame in a red bikini for Valentine's Day.
For the model's 69th birthday in February, she posted how "grateful" she is, noting that she has learned "gratitude, health and love are the keys to happiness!"
Alongside a montage of her past magazine covers, she wrote, "I have survived a lot, and what didn’t kill me, did indeed make me stronger, wiser, and I truly look at each day as a gift to celebrate! I love my life! I love my job. I’m always looking for products or projects that will make people happy! And that in turn makes me happy! It’s a Win win!"
She added how much she loves her family and friends, ending her post by saying age is nothing but a number. "So go ahead proclaim your age celebrate the years! Make those numbers your bitch! You got this! We got this!"