How to map palette to impression 7.3 colours and avoid dithering

[ReX1983]

Hello,

I have a Home Assistant dashboard that I want to show on the inky impression 7.3".
I get the snapshot via headless chromium, then convert it to 800x480, but now I am facing a dithering issue and the final result is low quality.

The snapshot has just 9 colours:

• light blue
• red
• violet
• dark yellow
• green
• black
• dark grey
• white
• light grey

I am not after colour accuracy, what I am hoping to achieve is to translate the above colour to the native colours of the impression screen, something like:

• light blue > solid blue
• red > red
• violet > orange
• dark yellow > yellow
• green > green
• black > black
• dark grey > black
• white > white
• light grey > white

Is there a way to achieve this in either python or command line?

Thanks!