Change color to X button on lightbox

i want to make the "X" in the the right side stand out in a certain color (#CEAD4C)

How can I do that?

I think it is not possible as the X mark is an image loaded dynamically when the lightbox is loaded. This is due to the transparency of the image, it is being hidden in the color of title. You may need to consider changing the title color to somewhat little light color.

Thank you!!