I have just installed ML magiclantern-Nightly.2017Jul03.7D203 on 7D.
I have experienced the same problem also with magiclantern-Nightly.2017Jun27.7D203.
With the ML Layout displayed in the Live View, I activate the RAW format in the Movie menu (after loading mlv_rec, mlv_snd and mlv_play) and then in Live View I press the Zoom(+) button (which normally magnifies the image 5 times so that you can do focus), I get this image:VRAM1.PPM. After about 1 sec, it turns into this image: VRAM2.PPM, that is a black and white image of what I normaly should see on my screen. Meaning, my Live View, magnified 5 times. From this position, it will not zoom again to 10x when I press this button again (which it normaly does). The solution is to press the trash button, which displayes the ML menu, then press it again, which turns it back to the black white image, but now, when I press the zoom button, it will zoom again, this time, the 10x magnified image is color as it should be. Pressing the zoom button again, will return the Live View to it's default state.
This problem appears even if instead of the mlv_rec I use mlv_lite.mo.
This problem does NOT appear for H264 (when RAW is off)
This problem does NOT appear when, instead of the ML Layout, by pressing the INFO. button, I display on the 3 Canon Layouts.
Please let me know how I can help you to fix that.