From the online PDF manual. There is more information on adjusting bass and treble but you get the idea.
The Tone Controls default setting is On. The TRIM
TREBLE and BASS Settings may be adjusted for the
currently selected Input Source. When the Tone Controls
are Disabled the previous settings for Treble and
Bass are bypassed from the signal path. To deactivate
Tone Controls perform the following:
1. Select the desired Input Source.
2. Press the TRIM Push-button on the Remote Control
until “TONE CONTROLS, On” appears on
the Front Panel Display. Refer to figure 61.
3. Press ◄ (Left) directional Push-button to deactivate
the Tone Controls. Refer to figure 62.
Note: When the TONE CONTROLS Setting is Off, the
BASS and TREBLE Controls will be inactive.
FullRangeMan, Green LEDs are cool. It is the red ones that are hot.