Mobile view logo background colour in wordpress

To change css in mobile view you need @media in you css. To apply on mobile view use @media as shown below

@media screen and (max-width: 768px) {

    Put your classes and IDs here

}

The above code will make your css apply only on those device whose Width is maximum of 768px in size.

You can use it with min-width also like this

@media screen and (min-width: 768px) {

    Put your classes and IDs here

}

The above code will make your css apply only on those device whose Width is minimum of 768px, In other words width must be bigger than 768px.

In your case you wanna change logo’s background then put your logo’s class/ID in @media and select your desired properties of those class/ID. If it don’t pick up your properties then try to use!important with property like this background: #fff!important;