Generate a highly detailed, black and white children's coloring image of a picturesque farm scene. The scene should feature a charming farmhouse and a classic barn nestled in a serene setting. The farm should be enclosed by a rustic wooden fence, and within this fenced area, include adorable cows grazing peacefully. The farm should be situated amidst rolling hills that embrace the landscape. The entire composition should radiate a sense of tranquility and provide intricate details for young artists to color and bring to life.