It looks like the display uses E Ink Gallery 3.
元太可望顯著受惠於Amazon採用彩色電子紙與Walmart採用四色ESL / E Ink expected to benefit significantly from Amazon’s adoption of color e-paper and Walmart’s adoption of four-color ESL | by 郭明錤 (Ming-Chi Kuo) | Medium
This is a reminder that in March 2024, Ming-Chi Kuo leaked that Amazon would release Kindle E-Readers using Advanced Color ePaper (ACeP) in 2025.
While this was initially thought to be misinformation following the announcement of the Kindle Colorsoft / Colorsoft Signature Edition in October 2024 (as the Colorsoft uses a custom display stack by Amazon based on E Ink Kaleido 3), the leak will turn out to have been correct after all if the Kindle Petit Color and its variants are released this year.