Do you ever take a picture and the colors don't come out the way you saw them? The camera is adjusting the "white balance" incorrectly. Most cameras, including phones, have a white balance setting. Which is either marked by "WB" or a thermometer. Adjusting WB is one of the simplest ways to get a better image, once you understand why every photo uses it.
White balance adjusts for color temperature. Our brains naturally decide what is white for us. Warmer whites get tinted with yellow. Cooler whites become tinted with blue. In editing programs there are two scales for adjusting your white balance. A blue and yellow shift (Temp, used often) and also a green and magenta shift (Tint, slightly used, mostly with artificial lights).
Most cameras, by default, have the the white balance setting on "auto". This setting tells the camera to decide on the neutral colored object and adjust the white balance. Neutral is a half way point between white and black, 18% gray. The camera has the toughest time making this choice when the colors; blue, yellow, green, and magenta are predominant without a neutral color for the camera to latch onto.
My Android camera has five settings for white balance. Auto, Cloudy, Sunny, Flourescent, Tungsten. The most common situations.
When a picture isn't coming out right, switch off auto white balance and pick the one that fits your current situation. If that still isn't working, try a different one. Lights have a very wide array of wavelengths.
My Canon t4i has eight settings; Auto, Daylight, Shade, Cloudy, Tungsten, White fluorescent, Flash, and custom. I rarely switch it off Daylight. This is because I save all my pictures in the RAW format which doesn't hard save WB, unlike JPEG. I leave it on Daylight, since that's my most common shooting situation. It's always best to save in RAW instead of JPEG if you have the option and plan to process your photo.
If you've adjusted the settings on your camera and the color still isn't coming out correctly, it's time to edit. Any reasonable editing program should include "warmth/temp" and "tint" controls. The first one you want to adjust is the "warmth" of the shot. If you have too much blue/cool, slide the scale towards yellow/warmer. The opposite is true for a shot that has too much yellow.
The shot of the Japanese iris's was shot with the daylight setting on my camera, but since it was a cloudy day, the colors came out cooler than what I saw and I lost the purple color. I simply adjusted the shot to be warmer and the colors became much more diverse and closer to what my eyes saw.
The next set is in order of Daylight, Auto, and Custom.
The first shot had too much orange in it for me. First I used the auto adjust function and it turned the picture much cooler than I liked. Lost the vibrance of the sun. The third shot I added coolness back into the shot to get a happier medium.
At times; WB is a personal choice. Sometimes I like the exaggeration of the orange in the first sunset picture. Also I'm still unsatisfied with the color of the ocean and the clouds. There's a drastic difference in how the light hits different portions of the photo. I went back and did a few specific WB adjustments to parts of the picture to get it closer to what I saw. Made the ocean warmer and the clouds cooler.
White balance can make or break a photo. Now go have fun with your colors!