I think that maybe the sun glasses were a specific color and/or luminance that was not in his clothing or his skin tone. If that was the case then the task was to use a qualifier to make a mask for that specific color and then de-saturate all of the other colors in the image to black and white. And again using that same mask you could change only the color of the sunglasses.
Thats one way
Thanks
Cris is Bliss
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