Assertion:
Netscape 4.x has a strange rendering bug with checkbox and radio button form fields. If a BGCOLOR attribute is declared for a table - or a cell within a table - the rendering boxes of any checkboxes and radio buttons (also INPUT FILE fields to a small extent) in that cell/table will not use the indicated BGCOLOR - it will instead use the BGCOLOR of the document itself. If you use Netscape 4.x, you will see this bug apparent at almost every large-scale site you go to.

BODY uses BGCOLOR=red to create extreme contrast to exhibit the behavior

TABLE with cellpadding=20 and bgcolor=yellow (extreme contrast to help see the behavior):
filler text
TD Cell 1
Radio button:     
Checkbox:     
File:     
TD Cell 1 		TH Cell 2
Radio button:     
Checkbox:     
File:     
TH Cell 2
filler text