Like many guys, you own a dark brown sport coat reserved for dates and special occasions. Although your sport coat adds a measure of style and polish to your outfit, it can sometimes be difficult to coordinate with the rest of your wardrobe. Understanding a few basic rules of color harmony will help you develop an aesthetically balanced ensemble.

Black, white and grey are all neutral colors. Grey is a neutral that goes well with many different skin tones and color palettes, while black and white require a small measure of color sense. A black shirt will look good on men with olive to dark skin but can overwhelm lighter skin tones. Men with light, pinkish skin tones will find that white shirts are often a more suitable option.

Near neutral colors include shades of brown, beige and tan. A tan or beige shirt can create a multidimensional appeal to a dark brown sport coat. Similarly, you can create a chic monochromatic look by layering lighter and darker shades of brown with your sport coat. When choosing your shirt, however, ensure that your pants, belt and shoes also contribute to the overall harmony of your outfit by utilizing colors with brown tones like mahogany or burnt umber.

Although warm colors like red, orange and yellow are strong potential options for a shirt, they should be used cautiously. If gold jewelry tends to complement your skin tone, citrus colors like orange and yellow will suit both your skin color and your dark brown sport coat. Red shirts should be chosen based on shade and saturation of color. Sport coats are designed to look somewhat rustic, so avoid highly saturated shades of red. Choose a subdued shade such as burgundy or scarlet, which will complement the rustic style of your coat.

Cool colors such as green, blue and violet are all appropriate options for a dark brown sport coat. Although each of these can work well with your coat, medium to light green shirts are perhaps the most visually appealing. Green and brown make a naturalistic combination that is well suited to the sport coat's rustic origins. Men with fair, olive or dark complexions will find that icy shades of blue and violet are well suited to their skin tones. Pastels are more suited to men with pale pink, creamy or peach skin colors. Although pastel and icy colors are similar, pastels are usually grayed and dusty whereas icy colors are crisp and clear.