Header Logo Color Change

Hello – I’d like to change the color of my logo on scroll, just like the color of the text on the navigation menu changes to be visible against the white background. Id like either the color to change, or have the ability to just upload a different color of the logo for it to switch to when the navigation bar sticks and becomes the white background. Any help is much appreciated!

The page I need help with: [log in to see the link]