For applying branding in a SharePoint website user first needs to login into the office 365 portal. To change the top office 365 ribbon colour and to apply (Logo) image in it we have to click on the ‘Company Profile’ in the left hand side navigation menu as show in the screen shot below.
A new webpage will open select the Custom theming menu from the left hand side navigation menu as show in the screen shot below.
Following page will open from here you can apply the ‘Custom logo’ image, apply a URL for clickable logo and also background image can be applied. As you can see below in the image I have selected an image for logo given a URL to this image so when we click at this it will navigate to another website.
User can also apply the Agent colour which is the square box in the top left hand corner, Nav bar background colour, its text and icons colour in the web page. After making all the required changes user will save the details. After save the changes will take effect.
In above screen shot you can see all the changes that we have made are all applied, so by following above steps you can also change the top office 365 ribbon colour and to apply (Logo) image.