made an edit for 4k. Now all 4 keys have a distinct color, this helped me tremendous!
[Mania]
Keys: 4
//Parameters
ColumnStart: 252
ColumnRight: 0
HitPosition: 430
SpecialStyle: 0
UpsideDown: 0
JudgementLine: 0
ScorePosition: 190
ComboPosition: 160
LightPosition: 405
LightFramePerSecond: 30
ColumnWidth: 50,50,50,50
ColumnLineWidth: 0,0,0,0,0
ColumnSpacing: 0,0,0
BarlineHeight: 0
KeysUnderNotes: 1
//Colours
ColourLight1: 160,255,64
ColourLight2: 255,64,64
ColourLight3: 128,172,255
ColourLight4: 37,33,8,220
Colour1: 24,37,1,220
Colour2: 15,35,37,220
Colour3: 37,4,25,220
Colour4: 37,33,8,220
ColourHold: 0,230,255,230
ColourColumnLine: 255,255,255,32
ColourBarLine: 255,255,255,128
ColourKeyWarning: 255,255,255
//Images
NoteImage0: mania-note2
NoteImage0H: mania-note2H
NoteImage0L: mania-note2L
NoteImage0T: mania-note2T
NoteImage1: mania-note1
NoteImage1H: mania-note1H
NoteImage1L: mania-note1L
NoteImage1T: mania-note1T
NoteImage2: mania-note3
NoteImage2H: mania-note3H
NoteImage2L: mania-note3L
NoteImage2T: mania-note3T
NoteImage3: mania-noteS
NoteImage3H: mania-noteSH
NoteImage3L: mania-noteSL
NoteImage3T: mania-noteST
KeyImage0: mania-key2
KeyImage0D: mania-key2d
KeyImage1: mania-key1
KeyImage1D: mania-key1d
KeyImage2: mania-key3
KeyImage2D: mania-key3d
KeyImage3: mania-key2
KeyImage3D: mania-key2d