The aims of this study were to describe wood color of Acacia melanoxylon with CIE color system and to analyze color variation between sapwood and heartwood among sites. Twenty trees were selected at four sites in Buenos Aires Province (Argentine). Destructive sampling was done, and one disc was taken at the base. Each disc was cut in radial boards (2 cm thick) and four zones were demarcated: sapwood, two transitions zones (or external heartwood) and central heartwood. The parameters x, y, Luminance, dominant wavelength (DWL) and purity excitation (EP) were measured. The x, y and DW values differed among sites; although for luminance and EP no difference was found. Differences between sapwood and heartwood values were remarkable for all the variables. Sapwood and heartwood chromospheres were optically different. Sapwood color was light and varied between green-yellow zone and yellow saturated zone. Heartwood color predominates from yellow to saturated yellow orange. DWL ranges were 564-574 nm and low saturated (23-28%). Dispersion variables inside heartwood showed no relationship between external and central heartwood sectoring; therefore, three zones with similar optical properties would be considered as heartwood.