Try red. Or blue.
gray brown and white
Mustard is a dark yellow color. You can make it by adding a little gray to a lot of yellow. Instead of gray, you may want to add a bit of brown.
Dark gray.
Brown!
To turn a color gray you need to add its contemporary color (the color opposite of it on a color wheel). Greens contemporary color is red but it will probably be to dark so add some white to get a nice gray.
Taupe.
Brown
gray,brown or blue
red,gray and brown
a porpoise's color depends on its type. the main colors of a porpoise is brown to gray and lighter brown, gray, but usually white on the belly.
either gray or brown
White and gray together will make a lighter gray. Red and green will make a brown. Light gray and brown together will make a neutral color, also called greige or a greyed brown.