Is there supposed to be a purpose to this? Personally, I don't think (accurate) Colour Analysis can be accomplished simply by taking the mean shades of every other horizontal line on the screen. A massive component of how cinematographers and art directors use colour to illustrate a story or reinforce the strength of a moment is through the alteration of colour. For instance, there are specific scenes in Up wherein a shift of mood is often conveyed through the adjustment of saturation.
Pay attention to the colour alteration present in Carl's face and the furnished surroundings after he reads Ellie's 'Stuff I'm Going to Do' scrapbook. It's subtle, but it means a whole lot of difference to viewers and filmmakers alike (the former on a relatively subconscious basis, of course).
Your methodology completely eliminates that variable, so I don't really know what you're expecting to get out of this.
Here's where this effect is most prevalent: https://www.youtube.com/watch?v=PvgVsVmusPg
Pay attention to the colour alteration present in Carl's face and the furnished surroundings after he reads Ellie's 'Stuff I'm Going to Do' scrapbook. It's subtle, but it means a whole lot of difference to viewers and filmmakers alike (the former on a relatively subconscious basis, of course).
Your methodology completely eliminates that variable, so I don't really know what you're expecting to get out of this.