How to capture better color with your camera

glare
Reflections in hood and glass
no glare
Polarizing filter eliminates reflections
“I’ll fix that in post,” is the mantra for so many photographers.  As long as you get the best possible exposure and shoot in the RAW mode of your camera there is a great deal that you can correct in the postproduction.  However, there is one thing that cannot be fully corrected that needs attention before you push that shutter release.
If you shoot RAW rather than JPEG you can change the color temperature much easier and more precisely in the postproduction.  For example when you open the photo in either PhotoShop or Lightroom the RAW image will give you a pull down menu that is similar to the white balance menu built into the camera.  You can pick Auto, tungsten, fluorescent, daylight, flash or custom white balance settings.  If you shoot JPEG these options are not available.
So, the mantra for the RAW shooter of, “I will fix that in post” can be done as far as white balance.  The problem with being able to correct a photo after the fact can give you the false sense of security that everything is fixable in post.
If you miss the exposure even in raw you can adjust the exposure in post, but the results will not be stellar.  Correct exposure will give you more dynamic range in the RAW image than one poorly exposed.
I recommend before you press the shutter to take the photo to do a custom white balance with your camera.  This is where you tell the camera the perfect white balance in that setting. 
expodisc
ExpoDisc is used to get a incident “white balance”
grey card
Grey card is used to get a reflective “white balance”
There are different devices to help you set the custom white balance.  I use the ExpoDisc as my primary device.  This is a device you put on your lens like a filter, stand in the place of the subject and point the lens back towards the direction of either the light or the camera.  This is called an incident reading.
Another great and inexpensive way to set your white balance is a grey card.  This is a 15% grey card that is calibrated to give you what would be the absolute middle tone in your histogram.  You put this where the subject is and filling the frame with nothing but the grey you set your camera to it.  The card is facing the direction of the camera.  This is called a reflective reading.  
If you take time to get a custom white balance you will save this step in postproduction and increase the accuracy of the color in your photos.
no glare2
Polarizing filter diminishes the glare in foliage
glare2
Without the polarizing filter you have glare in foliage
One thing that is not correctable in post is glare.  This is often everywhere in a photo.  The polarizing filter is the best way to correct for this flaw in photos.
Often fishermen wear polarizing sunglasses so they can see below the surface of the water and see the fish.  It helps cut the glare of the light on the surface of the water to see the fish below.

Polarizing sunglasses also help those operating motor vehicles.  The glare from the dashboard, hood and road can be removed with the polarizer.

The polarizing filter fits onto the lens of the camera and after it is attached the photographer rotates the filter while looking through the camera lens is able to decide how much of the glare they want to remove from a scene.  
Besides water and driving conditions glare is everywhere.  The landscape photographer uses the polarizing filter to improve the color of foliage.  Leaves and grass often have glare that a polarizer helps to remove and give a richer color that is not possible to correct in postproduction.
There is one more thing that a polarizer does besides cut glare, but this is a little tricky to grasp.  The polarizer can give you a darker sky, but this depends on the direction you are pointing your camera in relationship to the sun.  Only ½ the sky can be darkened.  Without going to a long explanation, you just need to rotate the filter to see what part of the sky is affected.  If it gets darker then you know it is working and if it doesn’t get darker it isn’t working.
The one thing you want to be careful about when using the polarizer is if the sky in part of the photo is in the area that will darken and some of the sky is in the area that will not darken in the same photo.  
When you listen to the weather report you often hear them talk about humidity.  This is how much water is in the air.  Humidity can be something a polarizer can help with as well.  The water in the air can add to the glare.  Using the polarizer can help in this situation.  The lower the humidity the richer the color because there is less interference between the lens and subject.  Where you will see this the most is in the sky.  In dry climates the sky will almost be black with a polarizer.
I highly recommend you own a polarizer and use it to improve your photos—because postproduction will not fix what it will.