What's BEHIND promo images? COLOR assignment ???

I have a unique background color problem on our site, due to the fact that custom made flash promo images can't be saved while retaining perfect background colors to adjoining other areas of the homepage ... unless I save those images in PNG format which the makes each of them at last 270 KB in size. I could however make them smaller by making the background color transparent. So here's the question ....

Is it possible to assign a default background color to that entire invisible block where those revolving flash promo images appear (thus causing that background color to appear in lieu of the transparency of the saved images)? Please let me know if this is possible and how it's done. Thank you.

Thanks a bunch houstonlively, that worked like a charm ... kind of ...

I completely forgot that you can't manipulate the order of the rotations themselves, nor the timing, at least not to my knowledge. Consequently the idea itself worked with your suggestion, but since none of the four flash images are identical ... with other visible stuff in the transparent areas ... this other stuff then becomes momentarily visible between the image changes. You got me on the right track though, I'll get it figured out ...