Can the color of egg a hen is laying change over time?

[Granitestater]

My little bantam Wyandotte, Peppermint, always layed a small white egg. She's now 4.5 yrs old, getting thru a cold winter, and after several mos of not laying (typical in winter in NH) at my place, here's what Im seeing: After seeing her sitting (prolonged) in the nesting box, hours later when she's vacated it, Ill take a look and there is a green egg. Now 2 wks later, same scenario and theres a flesh colored egg. It's happened at least twice with both colors. And the eggs are medium sized.
She is the only hen hanging around the boxes these mornings! Possible someone else slipped in or layed before she went in I guess. I have hens that lay those other colors.
Here's her picture at about 6 mos of age. She's the only bantam we have.
Wondered what you all think?

 

[JacinLarkwell]

No. Shades can change within reason (light tan to cream or bright blue to light blue) but colors cannot

 

[McChooky]

My pullets the same age and breed laid pretty blue green eggs last summer and fall but after I stopped free ranging them they started laying a darker egg. One now looks more green than blue. I've read the amount of sunlight they get can affect the shade on colored eggs.My chickens free range in the mountains under trees and actually get more sun in their run during the winter months lol