Checkout customization

Hi everyone!

As you can see in the screenshot, I was wondering how I could modify the colors of the main line and the 1-2-3 circles on top of the checkout page. I have tried every single combination on the color section but they remain grey or the same color as the background in which they are hardly visible.

Could someone help me please? Thank you in advance for your help.

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