512 RAM...37 GB storage, i guess it's a CRT monitor.
like the others suggested, it could be the monitor cable, shake it left and right and see if the colors change.
Thats exactly what is was , the cable connection to my HD flatscreen monitor. Just needed to jiggle and tighten it, color came back perfect, do not need to buy any video card. Thanks for something so simple and at no cost to me at all!