U-Net in Histological Segmentation: Comparison of the Effect of Using Different Color Spaces and Final Activation Functions Topics: Applications of Machine Learning; Biomechanical Imaging; Deep Learning in Bioimaging; Histology and Tissue Imaging; Image Processing Methods; Quantitative Bioimaging In Proceedings of the 18th International Joint Conference on Biomedical Engineering Systems and Technologies - Volume 1: BIOIMAGING, 386-389, 2025 , Porto, Portugal