The operation of V4.0.0 was suspicious, so I returned it to V3.9.0.
If you select black from the interface style, a WM-W800 style theme will be selected, echo light style for white and echo dark style for gold.
The reason why the direction of the cassette tape is reversed is that the original Walkman is in this direction.
this release is firmware downgrade only.
Please change the file name appropriately.
There is a technical text in this URL
https://github.com/mocochan-s9/echo-mini-v3.9.0-Sony-WM-W800-image-theme/