Kindle update, contrast again

People have long been talking about hacks or fonts for the Kindle which supposedly improve the contrast. I could never see how that would work, it seems to me you would need to change the hardware to make the contrast better.

The newest software update to the Basic Kindle promises again better contrast. With a small skeptical hope I installed it, but I photographed the Kindle first, for easier comparison.
Below the comparison photos. Even with Photoshop's measuring tools, I can't find any difference. (Oh, by the way, the same tools show clearly that the background is middle grey, not light grey as the manufacturers claim.)

Before update: 

After: 

I'm sorry to carp on about this issue, but it hurts my heart, because I could really love the Kindle if not for this single problem, that the screen is too dark. (That I seem to be in a small minority about it doesn't make it easier, but at least Mark Twain said it's the better place to be.    :-)

If/when Amazon makes a front-lit Kindle, like the Glow Nook, I'll buy it. It'll be my sixth e-ink Kindle*, all bought in the hope that This Time It Would Really Work For Me.
But I'm not bitter (not a lot). I think Amazon has really forwarded e-reading in a big way, when nobody else seemed to be able to.

By the way, these are the contrast/lightness readings (the tine circle on the left, first for the background and then for the text):

As you can see, the contrast is about one third of the theoretically possible.
I took care to photograph without glare in the screen, for maximum contrast.

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*I have Kindle 1, Kindle 2 Int, Kindle 3, Kindle Dx, and Kindle 4 Basic. (And the Kindle Fire, which is good, but doesn't do anything my iPad or Android tablets don't do.)