This tests shows the same linear gradient used with different values for the color-interpolation rendering property. The top bar is painted using the default color-interpolation value, which should produce the same result as sRGB. The middle bar is painted using the 'sRGB' color-interpolation and should be the same as the top bar. Finally, the bottom bar is painted using the linearRGB interpolation, which produces a result visibly different from the top two bars: the white to blue ramp is whiter, the blue to red ramp goes through a pinkish color and the red to yellow ramp turns orange before the similar sRGB rampl.
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The top two gradients must look the same, and the bottom gradient must look different to the top two. The rendered picture should match the reference image, except for possible variations in the labelling text (per CSS2 rules).