Full-color imaging is essential in digital pathology for accurate tissue analysis. Utilizing advanced optical modulation and phase retrieval algorithms, Fourier ptychographic microscopy (FPM) offers a powerful solution for high-throughput digital pathology, combining high resolution, large field of view, and extended depth of field (DOF). However, the full-color capabilities of FPM are hindered by coherent color artifacts and reduced computational efficiency, which significantly limits its practical applications. Color-transfer-based FPM (CFPM) has emerged as a potential solution, theoretically reducing both acquisition and reconstruction threefold time. Yet, existing methods fall short of achieving the desired reconstruction speed and colorization quality. In this study, we report a generalized dual-color-space constrained model for FPM colorization. This model provides a mathematical framework for model-based FPM colorization, enabling a closed-form solution without the need for redundant iterative calculations. Our approach, termed generalized CFPM (gCFPM), achieves colorization within seconds for megapixel-scale images, delivering superior colorization quality in terms of both colorfulness and sharpness, along with an extended DOF. Both simulations and experiments demonstrate that gCFPM surpasses state-of-the-art methods across all evaluated criteria. Our work offers a robust and comprehensive workflow for high-throughput full-color pathological imaging using FPM platforms, laying a solid foundation for future advancements in methodology and engineering.