The medical implant is made of one or multiple biocompatible polymers, where some of the polymers contain a dye. The biocompatible polymers have a reflective coating having colored coating. The biocompatible polymers contain dye film and a reflective layer. The coating absorbs corresponding dyes, when comes in contact with dye-containing body fluids. The colored or dye-containing polymers and polymer layers are provided for bordering the reflective and dye-absorbent coatings. The coatings are made of a dye film, which is heated and softened by using electromagnetic radiation. Independent claims are included for the following: (1) a device for fixation of bone or bone fragments, which comprises a bone plate having one or multiple implant holes； (2) a method for manufacturing a medical implant, which involves injection molding of the uncolored part of the medical implant in an injection mold； (3) a method for coating of the medical implant, which involves applying and drying the dye-containing polymer layers； and (4) a method for osteosynthesis, which involves positioning and heating the medical implant by using electromagnetic radiation.
