This coloring page offers a lot of fun opportunities for creative color combinations. I would suggest starting by giving the signs a vibrant red color, making sure to capture the details of the symbols and lettering using darker tones. Then continue by adding a touch of yellow to create an interesting contrast and complete the color scheme. For the worker holding the stop sign pictogram, I would use darker shades of red and yellow to emphasize the details, while the shovel worker pictogram should be highlighted with bright, warm colors like orange and pale yellow. Finally, to complete the look, use vivid blue, green, and hints of purple to create an eye-catching contrast to the red signs.