I have a vector artwork (fantasy map). It has several shapes and colors but nothing drastic like gradients, masks, etc. I need to export it to a large PNG file (45k x 45k pixels) but still maintain a minimally small file size (around 5mb or less).
I'm using the color hex codes to be imported into a terrain generator so the overall color count is minimal (~30). No matter what I do when I export, the PNG file is enormous (several gigs). I have been trying to export as PNG, use various lossy optimizers, re-saving as a lower resolution (since this is not for print I don't need a high res), etc. but nothing seems to work.
Can I limit the colors in my vector program (Illustrator) so when the PNG is exported it is a lower file size? Any other options/ideas to get this file smaller?