I believe the Soviet Flag s meaning were about these
Red: The Blood of the Common People that were massacred in October 1905, it was nasty.
Back in those days, Russia was still a Feudal Society the likes where a minority were Noblemens had most of the country s riches, the top ranks in the Russian Army and Navy were always Noblemen, and as you would expect they were often fighting to get the Czars blessings to what they were doing, and of course the Czar and his familly were allowed to do whatever they wanted but from what I heard, the Czar Nikolai II of the Romanov Dinasty (and also the very last Czar to rule in Russia in its complete history before the bolcheviks had exterminated them all) wasnt such a bad guy.
He might have been the Czar but he was also a father so that didnt meant his familly relatives were not an issue to think about.
The Czar Nikolai II had a son but his son had a serious illness and as a father he was often worried about him, back in those days there was no way to cure his son and there is still none today that I know of, and in 1905 Russia lost an all out War against Japan when the Battle of Tsushima came to a humiliating defeat for Russia, (The entire Russian Baltic Sea Fleet was sunk at the hand of the Japanese Fleet lead by Admiral Togo, regarded as the greatest Naval Commander Japan ever had, his flagship the Battleship Mikasa has survived such a long time and is known as not only the last Battleship of this era but shes currently anchored as a monument with a statue of Admiral Togo in Yokosuka Japan, this monument was restored with Admiral Chester Nimitz after World War 2).
But now with the real story about the colors.
In October 1905, the common people (mostly workers and peasants) showed up at St-Petersburg (also known as Leningrad) lead by a Russian Priest to ask for reforms in Russian Society, the only answer they got was the Royal Guard opening fire on the people, that incident is regarded as The Red Sunday or the October Red Massacre because of the blood shed of that day. That day the Communists chose Red as their special color for their flag and for what Communism stood for.
Next on the Soviet Flag was the Hammer and the Sickle, the Hammer meant the Workers, and the Sickle meant the Peasants, and the Star over that sign was a Golden Star, meaning the Army.
Before being called the Communists, they were originally called the Workers and Peasants of the Russian People Party.
Thats how the Soviet Flag was born in the first place.
I cant really tell about the White Army though.
And a little fact, Lenin, Trotsky and Stalin were all funding members of the Pravda the long time official paper of the Communist Party, but it was an illegal paper when the Czar was still in charge, until the Communists took over in 1917 thus leading Russia into Civil War with foreing military units to back the loyalists, mainly from France, England, the USA and Japan.
I hope this cleared up some questions