From Hubble Space Telescope pictures to the vocabulary used to describe the stars, astronomers and the media are coloring our universe, and they've been doing it for decades. While not intended to deceive, the efforts can range from the overly subjective to the absurd.

Earlier this year two astronomers from Johns Hopkins University announced they had determined the collective color of the cosmos, a shade of green that hypothetical viewers could see from afar. The idea was new and intriguing, an apparent answer to a question most of us had not thought to ask. Experienced science reporters and editors recognized the street value of the story and fell for it like paparazzi on a J. Lo sighting.

Brecher complains that "color is not what most astronomers and physicists think it is." It involves hue, saturation and brightness, he instructs, and it can't be thought of as just a wavelength or a frequency.

In the jargon of color science, Brecher explains why beige does not work: "It is almost impossible for a collection of blackbody emitters to give rise to beige, even allowing for absorption or emission line contributions."

On a more popular note, Brecher suggests the very vocabulary of astronomy is riddled with misleading color terms. Red giant stars like the bright and popular Betelgeuse, for example, are not really red, though they can sometimes appear so from Earth.

"If you could walk up to Betelgeuse, it would look white," he says.

That's because the star's light would overwhelm the color-sensing cones in your eyes. Only from a great distance, when the star is relatively dim, can the cones sometimes detect a hint of red. The vast majority of red giants, however, set off only the rods in your eyes, which cannot detect color at all. So most stars appear white, regardless of how they are classified.

Color conundrums go beyond the stars. Even the most famous images from the Hubble Space Telescope are no more than representations of reality, Brecher argues.

The quintessential Hubble photograph is a 1995 image of the popular Eagle Nebula, also known as M16 or the Pillars of Creation. The soaring structures had one of their red emissions converted to green -- by the astronomers who took the picture -- in order to highlight scientific detail. In "reality," no green was detected coming from the Pillars.

Interestingly, all Hubble images are created with black-and-white cameras. Ones and zeros are sent to Earth. Color is dropped in later with the popular Photoshop program.

Brecher and most other astronomers agree that what is done with Hubble pictures is not deceptive; the process is rooted in science, a way of extracting and highlighting information. However, the professor worries that the media do not always communicate when and how images are colorized.

Furthermore, he calls the process highly subjective.

"The color of objects that astronomers release are not really representative of a thing one might imagine exists, which is the objective color of a star or a galaxy," Brecher said in an interview last month during a meeting of the American Astronomical Society in Albuquerque, where he made his case before his peers.

"Color is a very, very subjective phenomenon," he said. "Color is in the eye of the beholder."

As an example, Brecher asks what color the Moon is. The instinctive answer is "white." Some might say yellow. And in certain sky conditions, it can look orange.

Brecher calls this question absurd, too, because it does not include the context necessary to allow an accurate answer. The dusty coating on the Moon's surface resembles finely ground charcoal. "If you bring average lunar material to Earth and view it in normal terrestrial lighting, it would look very dark." The color of the Moon and the light coming from it are two very different things.

"It is time for astronomers and the press alike to carefully distinguish between [color and light] when discussing astronomy," Brecher said.

With many objects and phenomena in space, color is only made visible by the power of a telescope. Planetary nebulae provide a good example. These bizarre and detailed structures -- often symmetrical bubbles or hourglass shapes -- are the result of gas that's been cast into space by a dying star. Different gases, such as oxygen, hydrogen and nitrogen, each generate a different wavelength, or color, depending on the local physical conditions.

Human eyes, even if very near to or inside one of these nebulae, could not make out the colors, however, because the emissions are too faint. They would see little more than a big gray area.

Hubble astronomers make multiple long exposures to draw out these colors. They also employ a different filter for each exposure to block all but a certain color of light. A digital imager records a grayscale image. After adding the color in Photoshop (and also eliminating artifacts generated by piecing the data together) the filtered images are combined.

In some cases, the colors are as true to reality as anyone could imagine. Other times, as with the Eagle Nebula, colors are changed for effect. Hydrogen and sulfur were each detected in red tones, so the hydrogen, which involved a shorter wavelength, was made green.

When images are taken outside the visible light spectrum -- in the infrared, for example -- the color choices are entirely up to the astronomers and photo processors.

"This is a representation of some kind to convey the information that Hubble has gathered," Brecher says. "It's scientifically sound, but their presentation is subjective."