Typically, most screens that you interact with during the day serve you with cool light in the background or blue light. This is good during the day, it is strong and it helps to see clearly the information you want. But the same blue light, after the sun sets, disrupts the inner cycle of the transition body from day to night. It influences the secretion of melanin that facilitates sleepiness and sleepiness after the sun sets.
Fortunately, in almost any modern operating system there is a tool that makes it easy to change the color temperature, even if its name differs from one company to another or from one firmware version to another. For those using an Android Pie smartphone, the option you're looking for is called Video Comfort.
As an Android user, in Settings, you find Visual Comfort in the Display section. There you can automate the automatic activation of the hot color temperature on the screen between certain hours by checking the "Planned" option. I opted for a warm light between 22:30 and 8:30 the next day. If you want to start sleeping earlier, you can manually turn on Visual Comfort by clicking on the check mark at the top of the window.
Depending on your personal sensitivities, on the same screen, you can choose a warmer or warmer color temperature when Visual Comfort is activated. Ideally, it would be to go as far as possible to the right, but you will lose a lot of the accuracy of the screen. In any case, the changes take effect in real time, you do not have to push on anything extra