Select Same Fills and Strokes for Shape Layers
Adobe Illustrator has a very useful feature in that you can perform a Select Same function that targets specific properties. For example, Select Same Stroke Color select all objects that have the same stroke color. Select Same Fill selects all objects with the same fill, etc.
It would be really useful to have something similar to this inside of After Effects. It is common to have to modify colors as a project progresses, and After Effects doesn't make it very easy to either access or change colors of Shape Layer properties without resorting to 3rd party tools like BQ Shape Layer Navigator or Ray Dynamic Color.
Arty Hunt commented
Another solution is to make a shape layer and parent each individual colour throughout your project to that parent shape layer's colour.
The problem with this is that if you have dozens or hundreds of different instances of a colour throughout the project, it's a very time consuming process to link them up manually and not worth doing on every single project when you may never need to change the colours.
Another solution that people have is using one of the effects that changes on colour to another, but I've found that this can have glitchy and inaccurate results.
a way of searching a project for all instances of a certain hex code so that they're ready to be linked to another colour would be ideal!