Colour can be one of the preferencial factors prior to making a decision when people want to make a purchase of a wood product. Impregnation treatment can alter the wood colour. This study investigated the colour change of young plantation Jabon wood due to impregnation using Polymerised Merbau Extractives. Colour evaluation was done using the CIEL*a*b* system. Investigations also included morphological appearance by Scanning Electron Microscopic and chemical change by Fourier Transform Infrared analysis. The results demonstrated that impregnation treatment using selected Polymerised Merbau Extractives i.e. PME22 and PME33, resulted in the colour change of the wood. Appearance of the impregnated wood was different from the original wood; it was like a 'new wood'. The colour was changed permanently. PME33 caused Jabon wood samples to be darker. The SEM results of untreated and treated Jabon wood showed apparent difference due to deposited cured polymerised Merbau extractives (PME) in wood vessels. Obviously, a certain amount of cured PME precipitated on the surface of wood vessels and filled in the cell wall illustrated by the cross section of treated wood. FTIR spectra revealed that impregnating treatment using polymerised Merbau extractives made chemical changes in the wood of new functional groups bonded to Jabon wood.