nuke.Root().addKnob(nuke.Enumeration_Knob('NewColorspace', 'NewColorspace', [i for i in nuke.allNodes() if i.Class() == 'Read'][0]['colorspace'].values()))
nuke.Root()['NewColorspace'].setValue(PROJ_COLORSPACE)
allOuts = [i for i in nuke.allNodes() if i.Class() == 'Group' and 'versionOut' in i.knobs()]
for i in allOuts:
    old = i['knobChanged'].value()
    new = '''
if 'NewColorspace' in nuke.Root().knobs():
nuke.thisNode()['colorspace'].setValue(nuke.Root()['NewColorspace'].value())
'''
    old += new
    i['knobChanged'].setValue(old)