Thanks again Michael.
I read your link and watched the video – both awesome by the way – and narrowed it down to “bx-wrapper” for the big white box showing on my site in IE9.
I updated my style.css to include
.bx-wrapper {
background-color: #313233;
}
#313233 being the dark gray I want as the background color…. no luck unfortunately in IE.
To troubleshoot and to confirm that it is the right code, I changed it to another color instead, and it does update in Chrome and Safari.
Any other ideas?