Salesforce Lightning has this amazing feature to allow admins to customize the overall theme elements, branding and color settings with just a few points & clicks and without a single line of code, isn’t it amazing.
1.Got to Setup in Lightning Experience
2. Type and Click Themes and Branding and in Quick Find.
3. You will see a list of predefined themes, either select one among those
4. Or we can create a new theme by clicking on the New Theme button on Top Right Corner. The New Theme Page will give you options to edit the following
|Brand Image||600 x 120 pixels image that will be displayed on top left corner of the Org|
|Brand Color||Navigation Bar Color|
|Accessible Brand Color||After you Override you can control Color of Buttons.|
|Page Background||Color of Page Background that you see|
|Global Header Background||Color of the Header bar, choose it wisely because it may mix up with Brand Image if the image contains transparency or it may mix with Action Icons on the top right corner|
|Brand-Based Color Palette||You cannot edit these but the these blocks show color of Button and Text in Salesforce.|
|Page Background Image||As its name says it changes the Page Background Image|
|Default Group Banner||An 1800×360 image which will be a default image for a Chatter Group|
|Default Group Avatar||A 200×200 pixels image which will be a default image for a Community Group Avatar|
|Default User Profile Banner||An 1800×360 image which will be a default image for a User Profile Banner|
|Default User Profile Avatar||A 200×200 image which will be a default image for a User Profile Avatar.|
For more details read more here.
Share your experience in the comments.