So you’ve spent months trying to wrap your head around digital color spaces and have finally been dragged, kicking and screaming, but mostly screaming, into an ACES-compliant workflow. Eventually, you think you’ve finally got it, and all the colors just *look the same* regardless of which bit of software you’re using or which stage of the pipeline you’re at. Yay!
Except one day, you notice when you’re playing back a test render that the colors just seem a bit darker (or maybe a bit lighter – both complaints exist online) than when you color graded the clip. Subtle, but definitely noticeable. Maybe it’s the color calibration of the screen? Nope, that’s fine. You check all your input and output transforms. Nope, they’re fine, too. You dive deeper and use MediaInfo to peruse the file’s hidden metadata in case the color space is being tagged incorrectly, but that all checks out. So what the hell?
Turns out VLC can also wreak havoc on color fidelity. Ugh.
So you know how you can change VLC’s video playback appearance in Tools > Effects and Filters > Video Effects? Don’t do that. Yes, if you nudge the gamma a bit, you can lighten (or darken) the image to get it closer to what you color graded. But you output for sRGB and hence encoded a gamma of 2.2, and VLC knows it’s sRGB and knows the gamma is 2.2, so why on earth should you need to manually tweak it? Plus you’ll save the setting, forget you changed the gamma, and henceforth all playback in VLC will be with a non-standard gamma and other stuff will start looking weird and it’ll take you ages to remember why….
Instead, go to Tools > Preferences > Video and play around with the output settings. Changing the Output from ‘Automatic’ to ‘OpenGL for Windows’ did the trick for us (on Windows 10): henceforth VLC playback colors perfectly matched the preview in DaVinci Resolve.
Note that you do seem to need to close then re-open VLC after saving the new preference: the change isn’t immediate. Beware also that some forum posts advise that OpenGL is somewhat CPU-intensive and so may lead to stuttering with high resolution or high framerate video. For that reason, some folks recommend DirectX or Direct3D9, or at least they do for earlier versions of Windows. Anyways, YMMV but video output is definitely the VLC setting to explore if you have otherwise unexplained issues with color during playback.
(If you have audio issues, you should probably mess in a similar way with the ‘Output module’ in Tools > Preferences > Audio. By default it’s set to ‘Automatic’. Specifying one of ‘DirectX’ or ‘WaveOut’ might make your problem disappear).