An in-vivo imaging device and method for performing spectral analysis include inserting the in-vivo device into a patient's lumen, illuminating the tissue lumen and collecting the light scattered and reflected from the tissue. The device may comprise at least six illumination sources for illuminating the tissue. At least two of the six illumination sources illuminate at a different wavelength in the blue spectral region, at least two illuminate at a different wavelength in the green spectral region, and at least two illuminate at a different wavelength in the red spectral region. The illumination sources are adapted to illuminate in groups of three, wherein each group of three illumination sources comprises one illumination source that illuminates in the blue spectral region, one in the green spectral region, and one in the red spectral region. Each group of three illumination sources illuminates simultaneously.
