If it's a Windows machine, I use the in-built tool to adjust the monitor settings until they seem more or less correct, with a known good (enough) screen for reference. This is very rough and prone to errors, but if the monitor has good enough sRGB coverage, I can usually get it to a point that I can get used to it and not be constantly distracted by it. Alternatively, you can get calibration profiles from some review sites, like LaptopMedia and NotebookCheck, but take that with a grain of salt - panel variance is a thing and can be quite significant depending on the manufacturer, so the profiles they have may not improve things at all on your end.