The geometric conditions of diffuse illumination, 8° observation, and specular light exclusion (SCE) are often employed to measure the surface color. The SCE condition is usually realized by setting light trap on the integrating sphere. Due to the size of the optical trap, different structures of the measurement instrument will lead to inter-instrument disagreement among the measurement of sample with different gloss. The reason of inter-instrument disagreement caused by different measuring structures is analyzed in theory; a measuring structure is designed to measure the SCE and specular light inclusion (SCI) results simultaneously. The gloss value is calculated from the SCE and SCI results. A computing model is proposed to modify the SCE measuring result based on the gloss value, and experimental verification is also carried out. Experimental results show that the modified model effectively reduces inter-instrument disagreement caused by different measuring structures, and is very suitable for engineering applications.