The two sisters are carefully measuring the slipper, one holding the slipper and the other peering down the length of the ruler. Both of their faces are scrunched in concentration, a symbol of their drive to determine the exact size. For coloring, the girls can be given a soft pink complexion to give them a subtle glow. Their colorful dresses can be alternating shades of light blues, purples, and pinks to give the image a smooth, peaceful atmosphere. Additionally, the slipper can be colored a bright yellow, with a golden shimmer to stand out. Lastly, the wooden ruler can be a warm brown shade, to balance the imagery.