Header - black on scroll

Hello Community,

I have recently launched www.woowoolondon.com and the main thing i’d like to change is the colour of the header (on scrolling down) from black to 3f51b5 ?

i tried here, within the CSS but that hasnt worked.

a:hover,
a:focus {
color: #3f51b5;
text-decoration: none;
outline: 0;
-webkit-transition: all 0.3s ease-in-out;
-moz-transition: all 0.3s ease-in-out;
-ms-transition: all 0.3s ease-in-out;
-o-transition: all 0.3s ease-in-out;
transition: all 0.3s ease-in-out;

Hello @woowoolondon,

I have already answered in your previous topic, let’s proceed there, please.

Kind Regards, Roman.