The conversion of RAW data captured by a camera can have artifacts in smoothness of various hues for varying chroma. To optimize smoothness and color accuracy, transform coefficients defining conversion of a standard color model to a target color model are determined. The RAW data is converted to data in a standard color model and the data in the standard color model is converted to data in the target color model using the transform coefficients. The process is repeated for various lightness levels and combined into a look up table to efficiently convert RAW data to data in the target color model for various lightness levels.