A portable illumination device, for illuminating an object through a
medium having an absorption coefficient, has a lighting unit including at
least two differently colored light sources for emitting light having a
color distribution and a control unit for adjusting the color
distribution. The control unit is adapted to receive a distance estimate
corresponding to the distance between the illumination device and the
object, and adjust the color distribution depending on the distance
estimate, such that light reflected from the object is perceived to have
substantially correct color reproduction.