That's why there's no shortage of calibration software but those often require having access to a colorimeter. Either that or you have access to a monitor like the UltraSharp 27 4K PremierColor so ...

Dell announced the Dell UltraSharp 27 4K PremierColor Monitor at Adobe MAX today. The monitor is the world's first 27-inch 4K monitor with a built-in colorimeter and Thunderbolt 3, according to Dell.

The Dell UltraSharp 27 4K PremierColor Monitor offers 100% Adobe RGB, 98% DCI-P3 and 80% BT2020, providing a wide range of color reproduction across different color space standards.