cobexer/html2canvas — comment on commit 044b612d6ed91ec39d28749085a41ec9be11e451
File:  line 0
By cobexer:

I just checked with Firefox: if no background is defined it returns transparent... so this would result in the same problem as before.
the best option would be to do both: have a default white background and draw a rect on top of that with the background from the rendered element