Quite possible. Years ago I did a text mode GUI and since I only had a monochrome monitor I chose the colours based on the shades of gray (and in fact it wasn't gray, it was yellow, a monochrome yellow monitor) I was seeing rather than how the actual colours were supposed to look like.
It looked pretty good to me but later, when I finally got a colour monitor, I saw the horror. Something like gray text on pink background, bright green text selection and cyan "controls"
.