the usual orange I see...
color changeable on these?
Yung'n He?
That is a standard Monochrome monitor, which typically came in 3 different varieties ( note I didn't say color, because they were in fact monochrome and NOT color monitors.)
The orange you see is actually called "amber", but there were green and white as well, depending on the phosphor used on the CRT.
OTOH, the other possibility is that - as machineit suggested - the monitor has been replaced.
If so, and if it is a Haas OEM replacement, then it is now an LCD monitor and not a CRT ( easy to tell just by looking at it )
If so, then yes, you CAN change the color. The retrofit kit has a board on it and I believe it is a rotary switch that lets you choose the "color"
It will still be monochrome display ( meaning no various colors, just the one ) but at least you can pick what you like out of the 3 available.