click:     refresh

    a:         move mouse left/right 
    b: shift + move mouse left/right 
    c: ctrl  + move mouse left/right 
    d: alt   + move mouse left/right

    color = rgba(a, b, c, d) with mapped domain
  
  
    a: -0.17786621128628832
    b: -2.292022887619761
    c: 2.2443550852640195
    d: -2.0457028222154143