1. A method for obtaining an interpolated color output value corresponding to a color input value based on a color look-up table which stores color output values of each vertex of a cubic grid of color input values, the method comprising the steps of: calculating plural weights for the color input value, each of the plural weights depending on color component values that together constitute the color input value, each of the weights corresponding to respective ones of plural tetrahedrons into which each cube of the cubic grid is dissected; storing the calculated weights in a temporary look-up table accessible by an index; executing a block of code to calculate the index, the block of code not including conditional branch instructions conditioned on a comparison of the plural component values of the color input value, the index being based on relative magnitude of the component values of the color input value; and applying weights at the indexed location of the temporary look-up table to the color output values in the color look-up table so as to obtain an interpolated color output value corresponding to the color input value.