I have an ADI Microscan 17" 1998

I bought this monitor yesterday, and was told that it took a while to
warm up.

When I turned it on, it looked pink for about 20 or 30 seconds and
then
went to a normal color . It worked perfectly all day after that.
I went out in the afternoon and when I got back at 9 pm the monitor
had turned pink again. I tried turning it off and restarting it,
but it is still pink. It be just that the cable needs to be removed
and replaced or I may have to
adjust the green gun setting inside the monitor.

If you have any experience with fixing a similar problem?