1. A solid-state image pickup device comprising: a first filter of a first color between a first filter of a gray color and a second filter of the gray color; a first filter of a second color between said first filter of the gray color and a third filter of the gray color; a first filter of a third color between said first filter of the gray color and a fourth filter of the gray color, wherein each of the first, second, third, and fourth filters of the gray color has a light transmission characteristic, wherein said light transmission characteristic has an integration value of transmissivity in a visible region, said integration value being substantially equal to that of a green filter.