think-cell automatically chooses the font color for label text from two specific PowerPoint design theme colors to ensure optimal legibility: PowerPoint's default font color and a color of opposite brightness (Text/Background Dark 1 and Text/Background Light 1). Change these two colors to change the font color throughout the whole presentation, e.g., dark blue instead of black, or light gray instead of white.
Make sure that one of the theme's Background Style options is selected in PowerPoint. This is required for PowerPoint to use the Text/Background theme colors correctly. When you convert an old presentation or template from a *.ppt/*.pot file format to the new *.pptx/*.potx formats, PowerPoint forgets to correctly set a Background Style.
For further information on how to set a Background Style correctly, refer to KB0129.
Some PowerPoint files are ambiguous in their use of design colors. think-cell then tries to deduce the desired font color from the file's available information. For details see Special cases further down on this page.
For some labels it is possible to apply a different color with the PowerPoint color controls. However, please be aware that think-cell may override any user-set font color at any time. This is necessary, because think-cell allows for completely automatic updates of charts when the data source (e.g., an Excel file) is changed. Updated data may result in a label being moved to a different background (e.g., from inside a segment to the outside or vice versa) and think-cell takes care to guarantee optimal contrast for optimal legibility.
think-cell chooses between two colors for labels, a primary font color and an alternative font color. think-cell's primary font color is the color that PowerPoint uses as its default color for text.
The second color, think-cell's alternative font color, should be a color of opposite brightness. Therefore, think-cell recommends that the color theme is set up in a consistent way, i.e., a light alternative color supplementing a dark primary color or vice versa. This is how Microsoft intended the Text/Background Light/Dark color pairs to work - compare the PowerPoint templates automatically installed with Office.
|Light Background Styles
(e.g., BG Style 1, 2)
|Dark Background Style
(e.g., BG Style 3, 4)
|Primary text color||Text/Background Dark 1||Text/Background Light 1|
|Alternative text color||Text/Background Light 1||Text/Background Dark 1|
For information on how to change these colors please refer to KB0105: How can I change the default colors of charts created with think-cell?
When a label is placed on a shape that is controlled by think-cell, typically a segment in a column/bar chart or an area in an area chart, the font color for this label is automatically chosen from think-cell's primary and alternative font colors to provide optimal contrast with the background.
When the luminance of the alternative color is similar to the primary color and the contrast therefore insufficient, think-cell uses either black or white for inverted labels to maximize the contrast from the background.
think-cell cannot know the actual label background because the color behind the label may not be the background color from the PowerPoint theme, but instead a different color set by a right-click on the slide background → Format Background. In this case the background may even be a gradient, a picture, a texture, or a pattern. The label may as well be placed on a custom PowerPoint shape or image.
This also applies to boxed labels. Here, think-cell uses the theme's background color for the label background and the primary font color for the label text.
Right-click on a textbox and open the Font color dropdown. Move the mouse pointer on top of the first two boxes of the palette as indicated in the screenshots. The second box shows think-cell's primary font color. The first box shows think-cell's alternative font color.
If the primary font color used by think-cell is not the text theme color, see Special cases further down.
If a PowerPoint template is ambiguous in its use of the theme colors, in our experience the intended font color is most often the body text placeholder's color. think-cell therefore uses this for the primary font color. The alternative font color is unaffected and chosen as described above.
If the body text placeholder uses more than one font color and the resulting font color in think-cell differs from your expectations, contact our support team.