In the Set BackColor dialog box, users can change the background color of a selected piece of text. To access the Set BackColor dialog box, click C1Editor's Format tab and then click the Background Color button .

The first column in the Set BackColor dialog box shows a gradient of colors in one part of the color spectrum, which gives users the option to select from different shades of the same color. Users can change the colors in this gradient by selecting a color in the rainbow spectrum (the second column). Once a user selects a different part of the spectrum, the gradient in the first column will change to reflect the user's choice, and the user can then select a background color. The selected color will appear in the window on the far left and its hexadecimal value will be revealed in the Selected Color text box. Clicking OK will apply the changes to the document.