Change Amount Channels In Pic

[rich2005]

My problem with your question is one of definitions.
Your two pixel example actually has 1500+ colours as: https://i.imgur.com/5GJSKTS.jpg
Whereas an indexed image with two colours, blue and yellow (three actually, I left black in to define boundaries) as: https://i.imgur.com/BpnZNe8.jpg

Raw Images ? Two types, Photographic RAW, various formats depending on camera make) Import only and a RAW data format which can be exported and opened. To open RAW-data you do need to know the original properties, dimensions, etc (or be good at guessing) as: https://i.imgur.com/Xl1u4cE.jpg