phoi_Make track color darker.lua

function main()
  local trackCount = reaper.CountSelectedTracks2(0, 1)
  for i = 0, trackCount - 1, 1 do
    local track = reaper.GetSelectedTrack2(0, i, 1)
    local prevColorNative = reaper.GetTrackColor(track)
    local prevColorR, prevColorG, prevColorB = reaper.ColorFromNative(prevColorNative)
    local newColorR = math.min(prevColorR - 30, 255)
    local newColorG = math.min(prevColorG - 30, 255)
    local newColorB = math.min(prevColorB - 30, 255)
    local newColorNative = reaper.ColorToNative(newColorR, newColorG, newColorB)
    reaper.SetTrackColor(track, newColorNative)
  end
end

reaper.PreventUIRefresh(1)
main()
reaper.PreventUIRefresh(-1)
reaper.UpdateArrange()