The Mixer panel in the Drum Deck, controls aspects of each pad, and like the controls in other areas of the Drum deck view, change colour to match the selected pad.
You can also adjust the Mixer panel parameters for all pads by holding shift on your keyboard while clicking on multiple pads to select several at a time (controls turn white in this case).
Double-click on a Mixer control to reset it to the default value.
Gain: Increases or decreases the maximum volume that the selected pad or pads can reach.
High: Reduces or increases the high-frequency content in the selected pad or pads.
Mid: Reduces or increases the mid-frequency content in the selected pad or pads.
Low: Reduces or increases the low-frequency content in the selected pad or pads.
Filter: Turn clockwise to engage a high pass filter, and counter-clockwise to engage a low pass filter, on the selected pad or pads.
Fader: Click and drag the fader up to increase the volume of the selected pad, or down to decrease the volume of the selected pad.