<p>Colorimetric sensors for volatile amine (VA) detection makes meat freshness monitoring visible and convenient. However, the sensing performance still needs to be improved due to low VA concentrations in the early stage of meat spoilage. In this study, we proposed the strategy of dye solution pH regulation to improve the sensing performance of the VA colorimetric sensor. Taking methyl red (MR) as the example, the pH of the MR solution was adjusted, and MR was then adsorbed on the aerogel to fabricate the aerogel-type VA colorimetric sensor. By adjusting the pH of the MR solution to 1 prior to dye adsorption, the sensor exhibited optimal sensing performance, with a sensitivity of 3.58 ppm⁻¹ and a maximum Δ<i>E</i> value of 108.90 ± 2.43. Compared with the sensors without pH regulation, the sensitivity and maximum Δ<i>E</i> of the newly developed sensor increased by 70% and 51%, respectively. This strategy showed good generality in various pH-sensitive dye systems. The sensor also successfully applied to the real-time monitoring of shrimp. A Δ<i>E</i> value higher than 62.16 indicated the spoilage of the shrimp. The enhanced performance was also validated in the freshness monitoring of other types of meat. The findings provided a facile and effective approach for optimizing colorimetric sensing performance in meat and aquatic products freshness monitoring.</p>