Fix VHS NTSC bugs

### Describe the bug <img width="720" height="1600" alt="Image" src="https://github.com/user-attachments/assets/a34b4599-7628-4e5b-922d-a67e5e647628" /> Image appears as greyscale ### Steps to reproduce Open Image Toolbox Go use VHS NTSC filter ### Expected behavior The filter would not show the image as greyscale and it would work ### Screenshots <img width="720" height="1600" alt="Image" src="https://github.com/user-attachments/assets/b40c34ab-fb2c-409b-8391-df2e5ff8ec01" /> ### Device Moto G Play 2023 ### OS Android 13 ### Locale English (United States) ### App Version 3.9.1 Alpha02 ### FOSS or Market Market (Google Play)