Update backgroundColor, fontColor and Readme of Header component

[manojleaton]

Describe the bug / expected behavior

Code and readme for the Header component needs to be cleaned up

What are the steps to reproduce?

1. Remove duplicate file in Header component folder named HaderBackgroundImage.tsx.
2. Need to get confirmation on backgroundColor and fontColor of Header component with Design, since we don't have specific figma screen for it, update and remove TODO comments from the code.
   Colors are correct; just need to remove the todo comments
3. Update Readme doc.

Screenshots / Screen recording

Code snippet / Link to minimum reproduction example

CODE HERE

Your environment information

Suggested fix

Anything else to add?