A number of countries flags are not blue and white, such as Belgium, Germany, Spain, Italy, Ireland, the Ivory Coast, Libya, Poland, and China.
White, Blue & Red. The English flag is red and white. The Welsh flag is red and white. The Scottish flag is blue and white
From top to bottom, the Russian flag has horizontal stripes of white, blue and red.
The blue and white flag symbolizes peace and unity.
The South Korean flag is black, white, blue and red. The North Korean flag is red, blue and white. The flag of the Korean Empire was white, blue and orangey red.
The bavarian flag is white and blue
navy blue and white
The colours of the Samoan flag are blue, red and white.
The colors on the flag of Finland are white and blue. Most of it is just a white background and the rest is filled by a blue cross that has fallen to the left.
not 100% sure from your description but sounds like Panama's flag.
It is a saltire, which is a blue background with a white cross.
There is a cross that is blue and the rest is white. So the colours on the finish flag are blue and white
The national flag of Finland does have only blue and white.