They received Polish style uniform, which was actually a simply copy of the 1er lanciers, but in scarlet. The red Lancers consisted of Dutch troops when they were first organized (Ironically, the recruit were ex-Hussars and -Cuirassiers), but after Russia, they were replaced by Frenchmen, and by the 1815 there were almost no foreigners left in the Red Lancers.
Even the British started copying Polish uniforms (Except for the Czapka's) after the Napoleonics.