2. That is to say, the colors arranged within 60 degrees in the color circle are collectively referred to as similar colors, and the colors within the range of 1 10 to 180 degrees are collectively referred to as contrast colors.

3. Similar colors and contrasting colors: Similar colors have a soft, orderly and harmonious feeling, and the matching of contrasting colors has a strong visual impact. Similar colors are good at creating a soft and warm feeling. Contrast colors are more likely to create excitement and excitement.

4. Cold and warm colors: warm colors will produce a warm, bright, lively and warm feeling. Cool colors can make people feel calm, steady and negative.

5. Brightness: high brightness will give people a relaxed and bright feeling, and low brightness colors will give people a calm and steady feeling.

6. Purity: High-purity colors look gorgeous, while low-purity colors give people a soft and elegant feeling.

7. Color lightness: In the case of the same volume, those with high lightness are lighter and have a sense of expansion, while those with low lightness are heavier and have a sense of contraction.

8. Forward or backward colors: those with high lightness have a sense of forward, and those with low lightness have a sense of backward.

9. Pay attention to the colors of adjacent billboards when making billboards above the door head, and use the color matching principle above to match the colors of adjacent billboards.