Assume your Github username is xxxx, Github supports a special profile repo https://github.com/xxxx/xxxx to render its README.md on your profile page https://github.com/xxxx above pinned repos.
However, it seems to only support markdown, which means I could not customize style (e.g. color, size, layout) through vanilla html, according to this answer.
Are there any workaround solutions to customize style of Github profile repo to make it look more fancy?
please click the link and read the documentation. Github Docs
Create a repository and type a repository name that matches your GitHub username.
select public and Click Create repository.
Create a readme.md file and type in your profile details
My github profile : Github Profile
Readme.md file example: Example
You can make your profile fancy by using many icons/logos/gif
you will not need any colors then, check out this resource which has the links to how you can generate a very colorful and relevant profile using some generators
a video which can help you of using the online resources which can make it easy for you
bit.ly/Improveyourgithubprofile <-- all the resources here
This is my profile and just with the markdown 
