Windows Explorer Text Color

[Janetb]

Files listed in Windows Explorer are for the most part in black text, but I
have noticed a lot of entries in blue text which I hadn't noticed
before....Why are some files black and some files blue (in the same folder)?

 

[R. McCarty]

They are compressed, as part of the Disk Cleanup utility that runs on
regular schedule. Compression simply means a string of characters is
replaced by a unique/shorter symbol.
Cat, Hat, Rat & Sat become C~, H~, R~ & S~. The result is smaller
sized files that are decompressed when called on. Compression is
done on files that have not been recently used. XP marks files with a
time stamp the last time they were accessed. This is why some files
are compressed and others are not.