What is significance of the pallbearers' red-black-red armbands during Navalny's funeral?

During Alexei Navalny's (Russian Orthodox) funeral on March 1, 2024, multiple photos show the pallbearers wearing the same red-black-red armbands on the left arm, as seen in Photos: Crowds attend Navalny funeral as Kremlin warns against protests , In pictures: Defiant Russians gather for Alexei Navalny's funeral , and Funeral of Alexei Navalny in Moscow – in pictures , for instance. Looking back, it seems that the (military) pallbearers during Gorbachev's funeral also wore similar armbands, but in this case those were black-red-black, as seen In Photos: Gorbachev Laid To Rest After Moscow Funeral That Putin Didn’t Attend . I am aware that plain black armbands are sometimes used as a sign of mourning, but I could find no reference to the red color. Is this typical for (Russian) Orthodox funerals or is this a political/cultural/regional thing? What is the significance of the red color specifically? Do they have a specific name, and what is their origin? ![Four Russian men with red and black armbands carrying a coffin ][6] ![Several Russian peoples along the side of a street; some men are wearing red and black armbands ][7] ![A Russian man wearing a red and black armband speaks with a military official ][8] ![A Russian man holds a black and white photo of Gorbachev while four military men with black and red armbands stand nearby ][9]