53FDX20B The picture became really blurry and has strong red and green coloring...

I would start 1st by checking all resistors ie.
RK43 2.2 ohm - 2W
RK47 1.5 ohm - 2W
RK51 2.2 ohm - 2W
RK55 1.5 ohm - 2W
RK59 2.2 ohm - 2W
RK63 1.5 ohm - 2W
If I were you I would also replace the convergence chips. From the above thread it's clear that they are of different quality so they may last different lengths of time (B&D is a good place to buy good quality ones).
I found a free pdf service manual for 53FDX20B on a Polish web site: http://instrukcje.elektroda.net/main1750.html
other models try here: http://www.webtronix.ca/hitachi/index.htm
http://www.asm-service-manual.com/List/Hitachi%20List%20ASM.htm
Download pictures from my repair (Password: delirious).
http://www.uploading.com/files/HGGLJLXC/Delirious.zip.html
Convergence amp ic bad
http://home.earthlink.net/~oleg.filippov/ConvergenceFix.htm
http://cmpalmer.blogspot.com/2006/11/fixing-my-own-tv-part-ii.html
http://www.hdtvoice.com/voice/showthread.php?t=28929