Color Scale
The Color Scale card controls the mapping from interpolated values to colors, including the color palette and the value range.
Color Presets
Five presets are available:
| Preset | Description |
|---|---|
| Viridis | Perceptually uniform blue-green-yellow ramp; good for print and colorblind-safe use |
| Turbo | High-contrast rainbow ramp; emphasizes differences in the mid-range |
| Red-Yellow-Blue | Diverging palette; suited for data with a meaningful center point (e.g., deviation from a target) |
| Spectral | Similar diverging palette with a wider hue range |
| Custom | Define your own three-stop gradient using the Min, Mid, and Max color pickers |
Custom Colors
When Custom is selected, three color pickers become available:
| Property | Stop | Description |
|---|---|---|
| Min Color | 0 (lowest value) | Color at the bottom of the value range |
| Mid Color | 0.5 (midpoint) | Color at the center of the range |
| Max Color | 1 (highest value) | Color at the top of the value range |
For a diverging custom scale, set Mid Color to a neutral tone (e.g., white or light grey) and contrast Min and Max with two saturated hues such as blue and orange.
Value Range
By default the range is derived automatically from the minimum and maximum values in the dataset. You can override it manually:
| Property | Description | Default |
|---|---|---|
| Range Min | Value mapped to the first color stop | Auto (dataset minimum) |
| Range Max | Value mapped to the last color stop | Auto (dataset maximum) |
Values outside the manual range are clamped to the nearest stop color — they are not hidden or excluded from the heatmap surface.
Transparency
| Property | Description | Default |
|---|---|---|
| Transparency | Global alpha of the heatmap canvas layer (0 % = fully opaque, 100 % = fully transparent) | 0% |
Reducing transparency lets you layer the heatmap over a background image or other Power BI visuals while preserving spatial reference.