Why raw histogram seems to be not "raw"?

[Lichtgestalt]

Hello everybody.
Small explanation: I'm using UniWB for some years, because it is much better to ETTR on Canon, and UniWB does great help with it. But also it annoys a lot, because often it is hard to see if the subject is in focus or not, and something more.
Some time ago I've discovered ML, and saw that it has Raw histogram feature, that should help me both to get out from UniWB and to make ETTR even more precise.
Month ago really non-desctuctive build was made (I mean bootflag on 5d mk III), and today I installed the latest nightly build.
I believe I've set all preferences required to see raw histogram, but the result is disappointing: when I call ML histogram by pressing "Light" button, very small histogram appears in the right bottom corner, and it is built using WB. I'm sure it is so, because I've shot two shots of the same scene that have the same A\S\ISO settings, and histograms are completely different.

So the question is: what I'm doing or understanding wrong? Is the histogram really built from raw, and is it possible to make it WB independent (and bigger in size, but it is less important).

[Audionut]

If the histogram has the EV bars on it, and slides with exposure without changing its shape, it's raw.

If not, it's YUV.

[Lichtgestalt]

Ok, but how to get raw histogram when viewing photos, and not just after the shot?

[Audionut]

That is currently not possible, in camera.

[gideonplus]

By the way is the falsecolor function based on RAW as well ?

[Audionut]

Only Zebras, Spotmeter, and Histogram, are raw based.  All 3 work in LV, and image review.

Also you can zoom in image review, and zoom out, and raw based displays are still visible.