How do you export colours more accurately in Adobe After Effects (for Instagram)?

Hex colors for consistency? OMG! Sorry, but that's utter nonsense on so many levels. Even if you don't get into any of that CM-related stuff, there's still a difference between an RGB color generated from a hex code and "baked" into the pixels of an image and the live rendered page content in your browser. It's one of those "In theory there's the W3C spec, but then..." Every browser handles this differently, even more so since some correct for monitor/ system color profiles, but only under some conditions while most don't and then there's this whole Pandora's box of images potentially being tagged with (wrong) color profiles and some browsers trying to fix that, t0o. You could dig into the Mozilla and Chrom development pages and really get scared.

As Angie was suggesting, the most painless way would likely be to dumb things down to not use any CM at all, but even then you still need to start by neutralizing your monitor color, which possibly is your biggest issue, anyway. Since all Adobe apps are aware of monitor profiles even when not explicitly using them for proofing, results can still deviate. In such a case you may even have to ditch a factory default profile that comes with your monitor, but if it's a HDR-capable 10 or 12 bit beast, that won't work because then colors will be utterly wacky. See how this unravels one after another? Lots of caveats.

Where the practical approach to video is concerned, some things that usually work:

• Define all your colors in genuine RGB colors, not Hex. Allow for alternate colors and tolerances since e.g. things like oversaturated red will be terrible for MPEG compression and definitely change color and cause aliased edges. Something to do with the color space transform in the CoDec.
• Same for other "pure" or very vibrant colors. As a rule of thumb the perceived saturation and brightness/ luminance should never exceed 90%, though there are exceptions. You'll learn to deal with this and develop a gut feeling.
• Reset all CM options in all programs, meaning plain sRGB/ AdobeRGB with no specific proof profiles or extended CM policies set.
• Create reference color charts with the base colors and your most used project colors. Sample them from screenshots to account for any color profiles - or absence of same. Repeat this for all apps if need be.
• Double-check your color settings based on the charts, i.e. loading ones from otehr apps into the current app and vice versa. Under ideal conditions this should not show any change in color or only minor deviations. If colors change too much, then something is fishy soemwhere. Do this roundtrip as long as needed for all apps until everything is okay.
• To account for Gamma shifts, applying a simple Gamma effect as the topmost adjusmtent layer can do miracles by simply dialling in the inverse of the assumed target Gamma/ target deviation. I typically use something like 1/1.2 = 0.835 when needed. This used to be common in the olden days, but contemporary encoders should not have that much of an issue and rarely require manually fiddling with Gamma settings..

Everything else comes down to experience and developing a somewhat relaxed attitude. You need to emphasize the overall perceived color rather than the actual color. I know that clients love to throw their CI folder at you and wave with Pantone charts screaming "But that's not our color!", but that's just not how this works. You will need to also have the patience to explain this to them along with working on your own understanding of the whole thing.

Mylenium