Future Mac keyboards may sport keys that light up with different colors depending on how they're being used, per a new Apple patent at the U.S. Patent & Trademark Office.

Patent number 8138687 is for a system for displaying multiple colors individually or in combination with one another. The system may emit red, green and blue light from light emitting diodes and may additionally provide white light to brighten the color provided by the red, green and blue light emitting diodes.

The white light source may also be used to increase the power efficiency of the system, thus increasing the lifetime of the system for displaying multiple colors. The white light source may be used to backlight the color provided by the red, green and blue light emitted by the light emitting diodes, or may also be used as an additional light source to the light provided by the red, green and blue light emitting diodes.

Here's Apple's summary of the invention: "Embodiments disclosed herein may combine light outputted from multiple light sources to create a combined light, also referred to as an 'outputted light.' The combined light may have different physical or perceptual properties from the constituent lights outputted by the light sources. For example, the combined light may have a different tint or brightness than either constituent light. Additionally, the combined light may share certain properties with at least one of the constituent lights, such as color.

"Generally, one embodiment of the present invention may take the form of a multicolor light source. The multicolor light source may include a first light source operable to emit a first light of a first color; a second light source operable to emit a second light of a second color; and a wave guide coupling the first light to the second light, thereby creating an outputted light having at least one aspect, other than hue, different from the first light and second light.

"Another embodiment may take the form of a method for outputting a light, including the operations of: activating a first light source to output a first light having a first color; determining that at least one aspect of the first light does not match a desired profile; and activating a second light source to output a white light in conjunction with the first light source; wherein the light and the white light combine to produce an outputted light.

"Yet another embodiment of the present invention may take the form of a method for providing multiple colors in a display system. In this embodiment, a first light emitting diode may be operable to emit white light, a second organic light emitting diode operable to emit red light, a third organic light emitting diode may be operable to emit green light and a fourth organic light emitting diode may be operable to emit blue light, wherein the first light emitting diode, and second, third and fourth light organic light emitting diodes may be configured to emit white, red, green and blue light in combination with one another. The first light emitting diode may be a white organic light emitting diode, and the first, second, third and fourth organic light emitting diodes may be included within a pixel.

"Continuing the description of this embodiment, the first light emitting diode and the second, third and fourth organic light emitting diodes may be arranged in a stack configuration. Alternatively, the second, third and fourth organic light emitting diodes may be arranged in a grid pattern and the first light emitting diode may be arranged in a stack configuration with respect to the second, third and fourth organic light emitting diodes, such that the first light emitting diode may be located beneath the second, third and fourth organic light emitting diodes."