Saving for web issues

I just bought my very own copy of photoshop 6.0 after using my school's versions of it. At school, if i save a graphic using "save for web..." it ends up as a .gif ad looks exactly like what I saw as a photoshop document. Now when I try it at home, the graphics look washed out and lighter. Does anyone know how I can fix this? Is it something with photoshop or with my browser (internet explorer v 5.5 or v 6 (both acted the same))

Thanks

the gif saves the image with set colors, up to 256.

when saving under jpeg compression, you would need to be careful about quality and size issues, the best way to do so is to play around with the quality to get the right size while keeping the image's original integrity.