My monitior is showing movies in red colour

Hmm, have you accidentally bumped any of your monitor settings? Possibly turned off all the green/blue coloring? That would explain it.

Try restoring it to default monitor settings that should solve the problem. If not... probably the Green and Blue receptor of your CRT must be broken, if this is the case, you may opt to buy a brand new CRT /LCD. I guess that would be a "cheaper" repair.
Good luck.