Colors of rear projection tv

Question

mu tv lost the blue quality.
it is greenish and does not look as clear as it used to.
the picrture is viewable but the contrasr and richness it had is now more dull
the red is there but too red
icannot get the sky to look blue
hard to distinguish the colors of outfits etc etc
i looked up the site you recommended but it does not mention any cd or manual. how many coolants do i need to do all the crt's in my tv