API Reference > imodeljs-common > Symbology > ThematicGradientSettingsProps > customKeys customKeys customKeys: undefined | Gradient.KeyColorProps[] The key color values that must be provided when using a custom thematic color scheme. Defaults to empty, unless using a custom thematic color scheme. In that case, this defaults to two key colors going from white to black. When using a custom thematic color scheme, there must be at least two entries in here. If there are not, it will revert to the default settings. Defined in core/common/src/ThematicDisplay.ts Line 66 Last Updated: 29 November, 2022