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

kanarelo/reportlab,Distrotech/reportlab,kanarelo/reportlab,kanarelo/reportlab,Distrotech/reportlab,Distrotech/reportlab,kanarelo/reportlab,Distrotech/reportlab,Distrotech/reportlab,kanarelo/reportlab