Discoloration of window

[Stephen G Sheldon]

Does anyone know what might be the cause of the bluish, red, and purple discoloration which appears at the center of this fixed pane double glazed window? Its tough to see from this picture but if you zoom in you should be able to see it. Thanks for any help you may be able to provide.

[CHARLIE VAN FLEET]

steve

many terms used

failed insulated glass
fogged insulated glass

but the seal looks like it has failed

cvf

[John Kogel]

Could it be a film, or a coating on the outer pane? It doesn't look like normal fog between the panes to me.

[Benjamin Thompson]

It's early stages of seal failure with low-e glass. The interior metallic coating is basically corroding. I would call it out as a failed seal.

[Jim Luttrall]

Some of the low E windows have a film suspended between the glass, though typically on higher end windows. That looks like a typical builder grade unit though so it may just be a failed seal.
Whatever the cause, the remedy is the same if it is between the panes. Replace it.