Aside from tgv's correct point that this is implicitly a recipe for something that isn't useful as a visualization, I think even if we were able to distinguish 4B colors and make sense of each pixel -> color assignment ... the math isn't on your side. You responded to a statement about nobody consuming a graph of 100B nodes. Suppose we don't have any concept of edge weight, and an edge is either present or not, but edges are directed, then you have 100B^2 (i, j) pairs for potential edges, each of which is either present or not (i.e. 10^22 edges, each of which is a bit).

4,294,967,296^2,073,600 is very large but 2^(10^22) is much much larger

That way of looking at it doesn't make sense. When visualizing a graph, you want to see the connections between the nodes; coloring each node individually almost never makes sense; and the eye cannot distinguish 4B colors.

You end up bucketing those colors into differences the human eye can see, so you end up with a much smaller domain.

You do something similar with 100B data points since you're not literally looking at the relation between individual nodes when all 100B are on screen at once.

> Each pixel can display 32-bit color

It's only 24-bits of visible colours.