changing of Iframe backgroung color according to parent

[vmahe]

Hi experts,
I have a requirement to change the background color of I Frame tag with respect to parent 's bg color. can you provide me the snippet for this.
when iframe is opening if open's with white background color. i changed IFrame color with allow transparency ="true" its working
But i need to change its back ground color with respect to parent color which IFrame tag is in. so when we change color in main page the Iframe background color also has to change.

[almostbob]

that would likely need to be done in the file that opens in the iframe
something like checking if(self.parent.background='blue') do something wonderful

not sure, dont use iframes much, use javascript less, but its an approach