Which looks better, navy blue or gray blue?

They all look good. Navy blue and gray blue are both darker. Navy blue looks rigorous, straight and regular. Especially, the trousers are more agile after being put on, which is suitable for young people and middle-aged people. Gray-blue is a combination of deep blue and sky blue, which comes from gray. Gray-blue has a refreshing feeling and looks clean and comfortable. So these two colors have their own beautiful characteristics.