Is Rosemaling Swedish?

In simple terms, no.  Rosemaling is the name of decorative folk art in rural Norway that flourished in the 1700's through the mid-1800's.

Sweden's folk painting goes by various, lesser known names, such as kurbitsmålning (or kurbits), dalmålning, and bonadsmålning. While the folk arts may appear to be similar, there are distinct differences; the colors, subject matter, and designs can be are very different from that of Norwegian rosemaling. 

The term rosemaling is sometimes mistakenly applied to Swedish folk painting. The fact Swedish folk painting did not enjoy the same surge in popularity as Norwegian rosemaling has led to confusion between the two arts.

Go here for more on the History of Rosemaling.

Vesterheim Norwegian-American Museum has a great resource for: What is Rosemaling.