Assuming same color depth and color mode, there should be no difference in color if the monitor is calibrated correctly. Nor should there be any changes in clarity if by clarity you mean contrast and brightness. Have you color calibrated your monitor? Some file formats take on different sharpness characteristics often times attributed to the type of compression used if any. For instance, the same image when viewed as a jpeg may seem less sharp than when viewed as tiff or bmp depending on the extent of compression.