This proposal seeks to enhance the documentation of architectural heritage. Precise color information (i.e. chromaticity, excluding lighting effects) as an intrinsic property of materials has not been accurately documented in the scale of large surfaces for historical buildings. Every day the materials of historical buildings are decaying and their colors are fading. The colors we can see today will not be the same as future generations can see if we cannot preserve the chromaticity information. We propose to develop a method to assist in recording the chromaticity of historical buildings with low cost and high efficiency based on the emerging High Dynamic Range Imaging technology. The significance of it lies in that by recording the chromaticity information, we can achieve more complete documentation for historical buildings and can detect color change of the buildings when measurements are done in a regular basis, which will provide important information for preservation planning