How to improve light quality from a bathroom exhaust fan?
You need a Daylight, Natural Light or Full Spectrum Bulb, going to Cool White is only a slight improvement &amp; may be what you have now (Soft White &amp; Cool White color is 2500K to 3000K). You'll need to check the package's or box's stated ratings, listing the color as 4500K up to 6500K.

GE &amp; Phillips have a single incandescent option, though the CFL's have a wider offering. This is an enclosed fixture &amp; not a sealed fixture so either of these will &amp; do work perfectly fine, LED's will not. However, overall bulb length may be limited by the fixture &amp; incandescent may be your only choice.