A focal trait of Photoshop is the program’s inherent readiness to achieve a desired result in numerous ways. Colorizing and re-colorizing are robust aspects of image editing for which the software gives you a massive set of tools and options, but, even the simplest of those will offer tremendous flexibility and predictability.
In this illustrated example, we will use a black and white photograph of silent movie star Louise Brooks, and will set her into a more colorful existence than the era’s technology could originally perpetuate her in.
Black and white images may have a Grayscale color profile assigned to them, which will translate every color tone you select as a shade of gray, ranging from pitch black to pure white. You want to rely either on the RGB – Red, Green and Blue – or CMYK – Cyan, Magenta, Yellow, Black – color profiles to manipulate colorized images. Though Photoshop offers a set of other color profiles as well, the RGB and CMYK models are considered as dominant standards. One thing to keep in mind though: the color tones you see with a CMYK color profile assigned to your image is a much more accurate representation of a printed result.
To change the color profile of the image, invoke the Image palette from the upper menu bar, and select the Mode sub-palette, which is, comfily enough, is the very first option. We can assign an RGB color profile here to our Grayscale image. The 8 bits/channel option essentially means that the resultant RGB image will be capable to accurately represent more than 16 million colors. Images with finer bit depth than this are often referred as HDR – High Dynamic Range – images. Since a setting of 8 bit RGB will give absolutely crystal clear results for the naked human eye, it is a safe bet to rely on this selection during work, not to mention that it will give you much smaller data size if you choose to maintain the profile all the while.
Once we have the image converted to an RGB color profile, we are ready to add colored pixels to the canvas.
Go ahead and select the Brush tool with the image activated. The upper menu bar changes, offering the various focal options that are relevant to this particular tool. Click the small arrow to access the core settings of the Brush tool. You may want to set a relatively high amount of hardness to the Brush, as this will prevent loose pixels from popping up on areas you will definitely not need them at.
An important side note: it is possible that you will get no direct visual feedback about the size of the Brush, depending on your Cursor Settings. If this is the case, then go to Edit – Preferences – Cursors. My experience is that setting the Painting Cursor dialog to the Normal Brush Tip option makes life easier. There is one advice I would like to give you yet: sometimes you may notice that your Painter Cursor have disappeared. This is the result of you pressing Caps Lock accidentally, – or deliberately, in which case I am ashamed to interrupt – which is the default Hotkey of turning off the layout preview of the Brush.
Now you are free to add color information to the image, yet the default, Normal behavior of the Brush tool will yield absolutely radical results. The pixels you paint in will have no regard to their surroundings at all. Essentially, you paint a new layer of pixels atop the originals. What we want to achieve here though is to keep the shading information intact, clean and uninterrupted. The Brush tool has a long row of behaviors defined in its Mode dropdown menu. Set this behavior Mode to the Color option and add some more pixels to the canvas. Since these newly added tones are sensitive to the lighting conditions and shading information you paint them on, it is but a matter of selecting sober prime colors to re-colorize the entire source image. As you will see, this is a very intuitive and comfortable way to colorize the original pixels. Have fun!