Logo Coloration

Hi, I like to have the transparent header when at the top of the page then as scroll down I like how it becomes solid. However while it is at the top of the page the text is white (on dark image) and when scrolling the header bar text turns black (on light header background color). How do i input two logos so that the logo can do the same as the text? I can generate a black and a white version of my logo easily enough each with proper transparency to look good), but I can’t figure out how to make the theme auto-switch the two?