a long tutorial on removing yellow cast from gifs
(image heavy! i am also still learning how to gif, so apologies if it's hard to follow!)
this tutorial assumes you have:
basic photoshop knowledge (specifically how to adjust curves, hue/saturation, and color balance)
know basic color theory (in this case, blue/purple canceling out yellow! you need to know what tone of yellow (golden/warm yellow, green tint yellow, etc.) you’re canceling out
a little patience with me! i’m pretty new to giffing and this is my first tutorial.
identifying the kind of yellow:
is it warmer/orangery? use more blue/cyan to cancel out!
is it cooler/more green? use more purple and pink tinted blues to cancel out!
complementary colors (across each other on the color wheel) are your best friend for correcting casts! in this case, we want purple to light blue to combat the yellows. use the color wheel as a guide!
make your gif — set your delay, make your frames a smart object, do your sharpening, and do one layer of curves (add life back into the skin and try to decrease yellow a little here. set your lightness with the RGB curve now).
i prefer a delay 0.05 or lower. i do smart sharpen based on the gif, and i also am not a cc who sharpens a lot. i also use vapoursynth, which provides some sharpening already.
a really good tutorial for basic giffing in VS and PS can be found here. @wonublr has fantastic tutorials, i highly recommend them.
here we can see delay with nothing else (left), versus the first set of curves and smart sharpening (right)! curves will look different for every gif! don’t worry about trying to match mine. i do slight adjustments on this first one.
already, we can see i’ve corrected some of the yellow by changing the green and blue channels!
this is the sharpening and first set of curves i used for this specific gif!
now, we want a cooling filter (especially useful on really yellow/warm gifs!) i select a color (you find this by going to photo filters, and then select color. this is where the color wheel comes in handy — you want a shade of blue or purple that is complementary to the yellow you’re trying to remove).
i lower the density on this to make it more natural.
next, we do our color balance to combat extra pesky yellows (gifs that are initially less yellow may not need this step!
i adjust shadows, midtones, and highlights very minimally (20→-20, never outside of that range, though it depends on the yellows you're trying to fix).
this helps add contrast and life back into your gifs as well!
on the left is just the cooling filter. on the right, i've done color balance! on both, i have masked the original gif (with only the delay) so you can see the progress!
next, we use our gradient map (once again, depends on how much yellow you’re removing. this will most likely whitewash your gif, so be careful and make sure you know how to re-add that life later if you use gradient maps!). you can make your own, but photoshop has plenty of presets. you want to stay in the purple and blue presents.
once you’ve selected a preset, change it to soft light blending and an opacity of 50 or below.
use hue and saturation to make your coloring how you like it (you’ll likely want to up red saturation to revive the skin!)
do one more layer of curves to make your coloring how you like it and ensure your gif isn’t whitewashed.
here we can see my second curves and what the image looks like with all these changes!
add a watermark if you have one, and you're all done!
the left is the original (only delay and my watermark), and the right is everything all done!
addition: two very yellow cast gifs with a mask showing the original vs. my correction following these steps :)