Dark green.
A more descriptive answer:
It depends on the exact spectra the light emits, not just what it looks to us.
When shining a green object onto a yellow light, the green object would absorb most of the yellow light while reflecting the green wavelengths. This would make the green object appear even brighter and more vibrant due to the contrast created by the yellow light.
A green object would appear dark or almost black under yellow light. This is because yellow light consists of wavelengths that are primarily in the yellow part of the spectrum, and it does not contain much green light. Therefore, the green object would not reflect much light back to our eyes, resulting in its dark appearance.
A lemon would appear green under green light because the object reflects the color of light that it does not absorb. In this case, a lemon's yellow color would absorb all other colors except green, which it would reflect.
A green object would look blaack in a red light because coloured objects absorb all colours except the colour they are, so a green object absorbs 6 colours (red, orange, yellow, blue, indigo, violet) and reflects 1 (green). In this situation, there is no green light to reflect and it can't reflect other colours, so it looks black. :)
It's called "A Blue Object" because when light of many colors falls on it, it reflects the blue light toward your eyes and absorbs all the other colors, including yellow. So if yellow light is the only light falling on it, the light is all absorbed, none is reflected to your eyes, and the object appears black.
When shining a green object onto a yellow light, the green object would absorb most of the yellow light while reflecting the green wavelengths. This would make the green object appear even brighter and more vibrant due to the contrast created by the yellow light.
A green object would appear dark or almost black under yellow light. This is because yellow light consists of wavelengths that are primarily in the yellow part of the spectrum, and it does not contain much green light. Therefore, the green object would not reflect much light back to our eyes, resulting in its dark appearance.
An object that reflects green and red light would be some shade of yellow or orange, depending on the proportions.
Even though youv'e given it the name "Yellow", the object is only yellow when there's some yellow light shining on it. You see, it absorbs all other colors of light, and only yellow light bounces off of it. That's why the light from that object that enters your eye is yellow light, and that's why you describe the object as looking "yellow". If there's no yellow light shining on the object, it looks black.
It's called "A Blue Object" because when light of many colors falls on it, it reflects the blue light toward your eyes and absorbs all the other colors, including yellow. So if yellow light is the only light falling on it, the light is all absorbed, none is reflected to your eyes, and the object appears black.
An object appears a certain color to you because it reflects that color of light and absorbs other colors of light. For example, a white object appears white because it reflects all colors of visible light (red, orange, yellow, green, blue, indigo, violet). A black object appears black because it absorbs all of these colors--and as a result, none of those colors are reflected back to your eyes. Under white light, the object appears yellow-green because it reflects both yellow and green light and absorbs all other colors. (Remember, white light has all colors of visible light in it). If only green light is present, there's only green light for it to reflect--so it will appear green. If you shined yellow light on it only, it would be yellow. If you shined yellow and green light, it would appear yellow-green again. It you shined red and blue light on it, it would appear black, because it absorbs both of those colors.
In blue light, a yellow object would appear dark or black because yellow absorbs blue light and reflects other colors. This means that the object wouldn't reflect any of the blue light, making it appear dark.
An object that reflects green and red light would be some shade of yellow or orange, depending on the proportions.
A lemon would appear green under green light because the object reflects the color of light that it does not absorb. In this case, a lemon's yellow color would absorb all other colors except green, which it would reflect.
The red light would be absorbed by the green object and the object would appear dark. The green object reflects green light and absorbs other colors.
A vey light yellow green or slightly murky yellow.
You would get a greenish color when mixing light blue and yellow.