Stir the rice, water, salt, and (optional) butter into an Instant Pot or other pressure cooker.
Lock the lid and cook on high pressure for 20 minutes in an Instant Pot or other electric PC (“Manual” or “Pressure Cook” mode in an Instant Pot), or for 16 minutes in a stovetop PC. Let the pressure come down naturally, about 15 minutes (If you're in a hurry, you can quick release any remaining pressure after 10 minutes).
In a small bowl, Stir the ¼ teaspoon of ground turmeric in 2 tablespoons of water until it dissolves. Add ¼ cup of the cooked rice to the bowl, toss to coat with the turmeric water, and let it sit for a few minutes, stirring occasionally, to absorb the color.
Fluff the rice with a fork, stir in the yellowed rice, and serve. Enjoy!