Here's one way to disable colored output in top:
Step 1: Run top
Step 2: Press the z key to toggle the color mode
Step 3: Press the W key to save the new setting
For reference, look at the top man page, specifically Section 4: Interactive Commands. There you will find the following descriptions of these two interactive commands:
W :Write-the-Configuration-File
This will save all of your options and toggles plus the
current display mode and delay time. By issuing this command
just before quitting top, you will be able restart later in
exactly that same state.
z :Color/Monochrome toggle
Switches the `current' window between your last used color
scheme and the older form of black-on-white or white-on-black.
This command will alter both the summary area and task area
but does not affect the state of the `x', `y' or `b' toggles.
Also see these related posts: