Bar colors have change but as far as I've seen, there still seems to be distinction to follow. Personally I like the my bar is red on the left and blue on the right. Old cabrinha bars were somewhat difficult for students to pay that much attention to the colors because the whole bar was pretty much black with some red highlights on the left side. Now the variations are something like white and black, white and green, yellow and blue, or even white and yellow. The more dominant or darkest color or shade is the right side.
Even if you rig up backwards the kite will fly the same. If you inverted your kite on a jump or something or it started looping on you, trying to decipher how to solve the problem and return the situation back to something safe will be harder and perhaps cause injury. You say to yourself, the left wingtip is in a jam or wrapped behind the leading edge, so you do something the Red side of the bar and the right wingtip feels the input. The kite launches and loops because you spent your first opportunity trying to fix the issue with what you thought was the correct side of the bar. Now you are being dragged along, confused, knowing your kite made one loop, might go through more loops, etc.... This is just hypothetical so no need for anyone to try and break this all down.
I see people rigged up backwards all the time, I ask why did you attach the red line to the blue pigtails and the blue line to the red? Even with a red and green bar this happens so I don't think color combos is less important than someone's consistency in rigging. I tell them the kite will still work, the chicken loop will still function the same if something goes wrong but you should rig up right, and be confident about it, that way if something happens out in the water, you do not waste any time pulling the wrong line, getting dragged and then asking yourself, "Did I rig wrong or cross the lines?" when at that point you should maybe be thinking, don't panic, might have to engage one or possibly both safeties.
What it really boils down to is people not taking enough lessons, not getting enough feed back from qualified professionals. The people that take the bare minimum in lessons, can water start and demonstrate riding skills, they buy a kite and go on there own but have no real guidance after that, no supervision except for that of their friend who is probably do the same mistakes if any. I've taught 10-12 year olds who in one lesson are more safety conscious and consistently rig up properly. On any given windy day, I see somewhere in the neighborhood of 1-5 backwards riggings an it is usually the same person or someone being chat up by someone else.
I think there already is a standard talked about quite a bit on this forum and in lessons. Know how to activate you safety mechanisms, know how to check proper functionality (this includes knowing your equipment i.e. kite structure, lines, trim strap, throw, chicken loop bar and color significance). Anyone not completely sure of themselves ought to be on the website of their kite brand, or on youtube watching how to videos and tech tips. Companies are trying to provide more to their customers these days by offering videos on how to use their equipment.
I'm curious what bar you have where the blue is on the right and black on the left though. Hopefully you are on the water or snow or grass by now.