A tool including a frame that includes an aperture and a boundary marker disposed about the aperture. The boundary marker includes a first marker region disposed about the aperture and a second marker region disposed about the first marker region. The color of the first marker region is different from the color of the second marker region. The tool also includes a color correction scale disposed proximate to the aperture. The color correction scale has at least a first color correction region and a second color correction region. The color of the first and second color correction regions each have an LCh value of between L=73.5 C=15.3 h=55.6 and L=32.5 C=11.6 h=48.3.