It is sometimes necessary to interpolate colors when you are interpolating values that do not contain numbers but rather RGB or HSL color code. This recipe addresses the question how can you define scales for color codes and perform interpolation on them?
Open your local copy of the following file in your web browser:
https://github.com/NickQiZhu/d3-cookbook/blob/master/src/chapter4/color-interpolation.html
Color interpolation is such a common operation in visualization that D3 actually provides four different kinds of interpolators dedicated for color supporting—RGB, HSL, L*a*b*, and HCL color space. In this recipe, we will demonstrate how color interpolation can be performed in RGB color space. However, all other color interpolators work in the same way.
Tip
D3 color interpolate function always returns interpolated color in RGB space no matter what the original color space it is since not all browsers support HSL or L*a*b* color spaces.
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