Yes the pollen filters behind the glove box are supposed to be white. I change mine every 15K miles. I believe that 30K replacement intervals are recommended but mine are dirty (grey color) around 15K miles.

Your dirty pollen filters caused your blower motor to work harder due to the lack of air flow.

The charcoal filters are only activated when you press the button on the console to eliminate outside stink. I believe the recommended replacement interval is 4 years. Since I don't activate mine that often, I replaced mine at 6 years.

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Ray
1998 Mercedes E320, 200K Miles
2001 Acura 3.2TL, 178K Miles
1992 Chevy Astro, 205K Miles