Change background color from 48,48,48 to 175,175,175 so that it is lighter so that dark text shows up better on it. Can't do bacgkround color for text labels, and PR2 is already white, so a light background and dark text seems like the best option.
Make the text larger, match the (rainbow) colors of the pose markers, remove the transparency, and add a space between 'step' and the number.