colors.py: normalize spelling of grey/gray colours, suggested by Paul Barass
colors.py: normalize spelling of grey/gray colours, suggested by Paul Barass

makinacorpus/reportlab-ecomobile,makinacorpus/reportlab-ecomobile,makinacorpus/reportlab-ecomobile,makinacorpus/reportlab-ecomobile,makinacorpus/reportlab-ecomobile