Normally laser has no color as it engraves (burns out material) however stainless steel and titanium metals react differently to variable laser frequency and as result color engraving is possible on both stainless steel and titanium.  In this sample dog photo was engraved on metal plate as a gift. Dog face has holographic look which shines in different colors.  This job was done with our state of the art fiber laser and variable frequency control module.