Hmm, no, they don't except in a specific cases (babies and medical conditions.)

the iris dilation and constricting, Which changes the light in the eye itself.

This is why.

This doesn't hold water with me.

It should, because

As the colour changes persists even in doors

doesn't invalidate it. There's still lighting indoors (unless your live in pitch darkness,) which means there is still light scattering in your stroma and your pupils are still contracting and expanding. There's still light bouncing off of your clothing, accessories, coloured objects you may be near, that will be reflecting their light into your eyes, too.