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: 2.7487762400890086
    b: -0.48449395027075015
    c: 0.4470558321267295
    d: 1.4777659787665396