The Color section in advanced Post Processing is used to control not only the appearance of color in the image but also the values or lighting in the rendering. Slightly adjusting the colors in a rendering and making them softer or more intense is one way of making your photos stand out.
The Tonemap checkbox turns on or off automatic tone mapping. Tone mapping is a technique to compress and HDR image into an LDR image. It does this along with fixing over or under exposures to achieve a balanced image with maximum contrast and a good range of color intensities. Tone mapping is default on and is recommended in most scenarios. If you wish to have full control over post processing yourself it is better to turn it off.
The Denoise checkbox turns on or off the post-processing noise reduction feature. Image noise is formed by irregular pixels which cause the image to appear "grainy." When the Denoise box is checked, the system will reduce the appearance of noise in the rendered image. Because this is a post-processing feature, the results will be the same whether it is checked before or after rendering an image. Using Denoise will not affect the current rendering time.
Explore exposure settings, ranging from very underexposed on the left to very overexposed on the right. Exposure gives the appearance of a photo that has a certain amount of light WHILE it was being taken. Imagine taking a photo in the bright sunlight. Increasing exposure can mimic this effect. Exposure also increases in areas of brighter highlights.
Adjusts the overall brightness in the photo, ranging from very dark on the left to very bright on the right. Increasing brightness will lighten all areas of the drawing, as opposed to exposure, which specifically focuses on highlights. Brightness looks more like lighting that has been manipulated AFTER being taken versus the lighting conditions while the photo was being taken.
Increase or decrease the contrasts in light and color in the image, making objects more or less distinguishable from other objects and the background. Increasing contrast causes bright spaces to become lighter, colors to be more intense, and dark spaces to be darker. Decreasing it causes a more neutral effect; lighting and coloring becomes more equal across the board.
Saturation is the vibrancy of color. Moving the slider to the left will make the photo look old and pale with soft colors; decreasing completely will result in a black-and-white photo. Moving the slider to the right will result in intense and vibrant colors.
Use this slider to change the hue in the image. Changing the hue is a good way to simulate light at different times of the day. The Temperature slider goes from blue/cool (left) to red/warm (right). Warmer light can be used to simulate the "golden hour" just after sunrise or just before sunset.
If you don't want to adjust the temperature manually, you can always use the Auto temperature button instead.