marking = None
for markingTested in Document.Data.Markings:
    if(markingTested.Name == jsonParam['name']):
        marking = markingTested
        break;
if(marking == None):
    marking = Document.Data.Markings.Add(jsonParam['name'])
marking.Color = Color.FromArgb(jsonParam['color']['a'], jsonParam['color']['r'], jsonParam['color']['g'], jsonParam['color']['b'])


