Spreadsheet Widget Headers not showing after adding custom CSS

I am having trouble with my spreadsheet headers showing up in ie.  Can you help?

The issue seems to be caused by injected CSS. Please also add the next CSS to fix the visibility issue in IE and other browsers.

#col_A, #col_B, #col_C {
visibility: visible;
}

If you need any further assistance, please let us know.

I have missed the !important statement.

The actual code:

#col_A, #col_B, #col_C {
visibility: visible !important;
}

Thank you.  This works, but it now shows the A, B, C I was trying to hide.  Any ideas?

Here is a screen shot. 

You can try the next CSS to hide the text by applying the same font color as background color.

#col_A, #col_B, #col_C {
color: #4b6e70;
}

#col_A:before, #col_B:before, #col_C:before {
color: #FFFFFF;
}

It should work unless the text is selected.

Thank you.