You could try Moen or Delta. They both have similar colors in their modern lines, but I don't know that the pricing is all that much different.

When in doubt, check Amazon, lol. Type modern brushed gold in the search bar and lots of Kohler will show up but you'll see other brands mingled in. Moen has a brushed gold but I have no idea how it compares to the Kohler shade.

white owl paints has a cleopatra gold that is a dead ringer for Kohler Vibrant Modern gold.

Just found cabinet hardware which is a pretty close match to Kohler vibrant Moderne brushed GOLD. It’s by Richelieu and the color is aurum brushed gold. Hope this helps. It’s has been a search that I have lost sleep over. Lol