Hi @sailor_vic,
Welcome to the HP Forum!
Thank you for joining the HP Forum community. It is a great resource for information, tips, and solutions that have helped others. Here is a link as a guide should you have any concerns or questions about the process:
First Time Here? Learn How to Post and More
I grasp that you are having an issue printing in color. You printed a diagnostics page and the inks show approximately half full and print head health is OK. When you tried to print each color individually only the yellow printed.
Here is a link that I think will help with this difficulty:
Please let me know the results.
If this post helps you to resolve the issue, please pay it forward by clicking "Accept as Solution", to the right of the "Thumbs Up Icon". You can click the thumbs up icon to show gratitude!