Color constancy algorithms under non-uniform illumination are particularly hard to evaluate. Ground truth illumination measurements are either inaccurate or only sparsely set in the scene. We provide a dataset of four scenes, captured under combinations of 6 spectral filters. After the capturing, the scenes were painted gray and recaptured. This protocol provides pixel-wise ground truth, but discards interreflections. We assumed this to be a reasonable trade-off to evaluate our algorithms.