I've noticed how Umbrella Academy and several other recent shows use a very constrained limited color palette. Is there any way to use HitFilm express to shift color in footage toward a limited palette ?
Several. Most of the color grading tools can be used for this, but there isn't a magic setting we can just say, "Oh, use this.*"
I'd like to note that shows that use limited color palettes start in pre-production and carry all the way through. They didn't magically color grade that shot to a limited palette, they planned that palette ahead of time and painted the set, chose the clothes, colored the lights and adjusted the makeup with that palette in mind.
If you're aiming for a limited palette look it's all going to begin before you shoot - planning is key.
*Closest thing to the magic fix is the "Grading Transfer" (Add-on) effect, but even that starts with planning for the shoot.
Does express have the posterize effect? You cant choose the colors but it reduces the number of colors.
@Dimipapa Posterize IS in Express, but Posterize works by reducing the LUMINANCE channel, so it won't really give the effect desired.