Originally my commits would just say "Username committed...", but now they say "Username authored and committed...", and it appears gray and no longer lists me as a contributor. It lists me as both the committer and author and shows a default image instead of my profile pic.
Each Git commit has two user names associated with it, the "author" and the "committer". Usually they are the same (in which case Github shows "X committed"), but they might be different if one user amends or rebases a commit originally created by another user.
In Github, usernames show up grey if the email address is not associated with an existing Github user. You can check the email addresses associated with the commit by running
git show <commit-id> on the command line - I'm not sure if there's a way to do it from the Github web interface.
One reason this might happen is that your email address is set incorrectly in Git on the computer you're working on. From Github's Setting your commit email address in Git article:
- Open Terminal.
Set an email address in Git. You can use your GitHub-provided no-reply email address or any email address.
git config --global user.email "email@example.com"
Confirm that you have set the email address correctly in Git:
git config --global user.email firstname.lastname@example.org
Add the email address to your GitHub account by setting your commit email address on GitHub, so that your commits are attributed to you and appear in your contributions graph.