Color is also known as hue. Each hue is a specific spot on the color spectrum. A spectrum can be as simple as a band, or wound up in a wheel. Measurement of value is from black to white. The range from black to white is called value.
Contrast is the degree of separation between values.
Whereas brightness adds white to an image, the lack of brightness tones the image. No saturation on top, to full saturation on the bottom. Saturation is the measurement of color intensity. The lack of saturation should remind you of black and white television. Just don't worry.