Start by Copying the embed slideshow link in picasa (HERE's how). NExt,change the "RGB=0×000000"portion in the code you copy . The Example below has replaced the 0x000000 to FFFFFF to create a white background. Note: Only replace everything after the RGB=
IF you want something more colorful, check out this. There are 500+ samples to chose from.
EXAMPLE:
<embed src="https://picasaweb.google.com/s/c/bin/slideshow.swf" width="800" height="533"wmode="transparent"flashvars=
"host=picasaweb.google.com&hl=en_US&feat=flashalbum&RGB=FFFFFF&feed=https%3A%2F%2Fpicasaweb.google.com%2Fdata%2Ffeed%2Fapi%
2Fuser%2Fandrew.joanisse%2Falbumid%2F3650428
57781624465%3Falt%3Drss%26kind%3Dphoto%26aut
hkey%3DGv1sRgCLyf8qSznIO6Eg%26hl%3Den_US" pluginspage="http://www.macromedia.com/go/getflashplayer">