This was something I struggled to wrap my head around as I began to explore islands outside of my first. But, to get red research, you need to find the coinciding ancient technology. Ancient technology is scattered across all islands - so once you’ve found an island home to red ancient technology, you’ve found the gateway to red research. I’d immediately colonize the island and set up a shipping lane to your first island. Consistently trading red and green research between your islands will ensure you’re always rich in both, saving you a world of stress (quite literally) as you try and develop new skills within the game.