Natural dyes are preferred over synthetic dyes in areas with strict safety regulations due large spectrum of hues. Clitorea ternatea, (CT) also known as bunga telang, is a plant with potential as a natural dye. This study employed in situ polymerization to synthesize natural dye microcapsules, utilizing polymethyl methacrylate (PMMA) as the encapsulating wall material and CT extract as the core material. This study aims to investigate the effect of extract pH on the physical properties of microcapsules. An aqueous-in-oil emulsion technique was employed to create microcapsules at three different pH of the CT extract (i.e., pH 2.3, 4.7, and 4.9). The structural, morphological, and size of microcapsules were examined using Field Scanning Electron Microscopy (FESEM). The microcapsules synthesized at pH 4.9 exhibited a size of 1.03 ± 0.15 µm, featuring smoother, less fissured surfaces, and enhanced sphericity. These characteristics indicate improved stiffness and stability compared to those produced by extracts at other pHs. The encapsulation efficiency of CT-PMMA can be observed from the light absorption profile of the extracts and CT-PMMA microcapsules. The maximum absorbance (λmax) of the CT-PMMA microcapsules was lower than the extract, especially for the pH 2.3 extract. Among the evaluated extracts, pH 4.9 extract proved to be the most optimal for encapsulation, yielding the best results in terms of stability and capsule formation. Considering their great stability, it is anticipated that the CT-PMMA microcapsule samples developed in pH 4.9 extract in this study can be utilized as natural dyes for the textile industry.