text on background       ratio  normal text (4.5)  large text (3.0)
ink on paper            14.76:1  pass               pass
ink on canvas           13.62:1  pass               pass
muted on paper           6.46:1  pass               pass
muted on canvas          5.96:1  pass               pass
brand on paper           6.67:1  pass               pass
brand-ink on brand       6.67:1  pass               pass
ok-ink on ok-bg          8.22:1  pass               pass
err-ink on err-bg        6.94:1  pass               pass
danger on paper          6.57:1  pass               pass
#9aa5b1 on paper         2.50:1  FAIL               FAIL
