This is not my original idea, but based on a Twitter Post from @mrs_janusz, and other techie people, I created my own template to share with anybody who would like to customize their own Google Keep Headers, similar to what you see below.
Here is a link to the Google Keep Headers Template in Google Slides that has all the slides you can customize to make your own headers.
Make a copy of the Google Slides presentation to customize with your own text, colors, and icons.
To download a slide as an image: File → Download → JPEG Image
In Google Keep, upload the image to the note, choose the matching color, and be sure to pin it.
Let me know below if you have any questions, and be sure to tweet and share with me @lisagceja your own customized Google Keep Headers!