Black & White vs Color Infrared.

 True infrared images are from a wavelength of equal to and greater than 720nm. Popular filters are 720nm, 760nm, 850nm, and 950nm. All these filters produce a monotone image with little to no color. Since plants reflect infrared more than surrounding objects, the leaves appear white. In some cases, the infrared light will pass through the plant and actually make the plant seem translucent. Color filters pass both visible and infrared light depending on the filter and produce false colors.

When attempting color Infrared images, the key to success is white-balance. Most cameras have an Automatic white-balance setting that must be disengaged. If your camera has a custom white-balance setting, you can either set the white balance to something neutral like concrete or off greenery like trees or grass, both will have different effects. If you white-balance off green, anything green will become white in the photo. The sky will come out the color of the filter. If you white-balance off something neutral like concrete, it will be some shade of gray, the sky will be the color of the filter, but the greenery will be the opposite of the filter on the color wheel. A blue filter gives you a blue sky and yellow leaves. A green filter gives you a green sky and purple leaves, a red filter will give you a red sky and blue leaves.

When using a Red filter that gives you a red sky, some photographers swap colors, so the sky is blue instead of red.

The upper-right is the image straight out of the camera. The lower-right is color swapped red for blue. The upper-left image is the lower-left image with the color stripped away, and the lower-right is a visual spectrum image (normal image, no infrared).

In some cases, a camera might not have the ability to set a custom white-balance, it which case you might be able to set an incandescent or fluorescent, white balance, the idea being to separate the colors out of the image. What happens if you use the automatic white-balance? If you attempt to use automatic white-balance, you will end up with a red or purple image in the case of infrared images, or some other color depending on what color filter you attempt to use. 

These are 720nm and 950nm images with Automatic White balance with a full-spectrum camera, so what you end up with is a monotone image with only one color. Newbies usually post this kind of picture with a "what did I do wrong" attached to it. (these are my first attempts at a color image). A third technique is to take the picture in RAW file format and white-balance post-process using the RAW converter software available for your camera. You create a DNG profile for your images and never have to worry about a custom white-balance again. Personally, I haven't had good results in post-process doing it that way, but I don't have a mainstream camera, so it will be whatever works best for you.

I've mentioned converted camera's, but what does that mean? Every camera has an Infrared/Ultraviolet blocking filter over the sensor. In order for your camera to take infrared images, this filter has to be removed to receive the most amount of Infrared light.  Without that process, Infrared becomes difficult in the case of B&W to impossible with respect to color images. You will have the choice of "full-spectrum" conversion or conversion to a specific wavelength depending on what the company offers. If you get your camera converted to 590nm, for instance, you will be able to take some false color and by adding additional filters to the lenses, higher wavelengths, for instance, you can take a 760nm picture if you have a 590nm conversion, but you can't take a 590nm image if you have a 760nm conversion. 

With a full-spectrum conversion, you can use any wavelength you wish, including using a "Hot Mirror" filter that allows you to take "normal" images again as if you never had the conversion. It's like having two cameras in one.

If full-spectrum is so great, why get a conversion to a specific wavelength and limit yourself? Some cameras don't have an electronic viewfinder. If you have an older camera that has a pentaprism, putting an infrared filter over the lens will block you from seeing any light. This makes infrared photography difficult, but not impossible. Before electronic infrared was available, you had to use infrared film. This meant using a tripod to set up the shot and focusing, then screwing on the filter to take the photo. This was followed by a prayer that you guessed your exposure correctly, and you didn't find that out until you processed your negatives. Now at least you can post view your images. An electronic viewfinder means you see what the sensor is seeing, so what you see is what you get. If you decide to purchase a dedicated camera, look for this feature, it makes life easier.