Nice looking bowls/platters Ganchik, Good way to show that wood selection is only half the final look, a finish or technique can drastically alter the other 50%.
I'm a big fan of ammonia fuming, lots of variations can be had. White oak gets that nice rich brown, red oak will get a greenish cast. Cherry tends to go brown/grey. Any wood with high enough tannin content will darken, but the neat thing is you never know what you get until you fume and apply a finish.
My favorite source for ammonia is the 10% "Janitorial Strength" from Ace hardware, about $5/gallon and plenty strong to turn some prime white oak into a chocolate brown after 6-10 hours.