Attaching links to images to show the difference in contrast. As you can see, for reading text, any of these devices should be fine. But, when it comes to contrast, KO3 is better.
https://i.ibb.co/B3LdhhH/ko3-vs-ka1.jpg
https://i.ibb.co/QmkKTkR/ko3-vs-kf-text.jpg
https://i.ibb.co/hgQ8Rzv/ko3-vs-kf.jpg