Color is a visual sensation that occurs in our eyes. The colors of reality affect our vision and our eyes are capable of recognizing millions of different colors. When we talk about print or computer media we have to understand that they will never be as rich as reality, but they can achieve a very complete color range. In the case of screen colors, these are generated by sources with their own light (the screen) and are called additive colors, because the more color we add, the lighter the result, until we reach pure white. On the other hand, in matter colors (inks, paints) the process is subtractive: the more color we add, the darker the result, until we get to pure black.
In the "light" color, the more color we add, the lighter the result. In the "matter" color, on the other hand, the more color we add, the darker.
On-screen color is defined by its depth, that is, the different number of different colors that a pixel can display. And, according to this depth, we can talk about different types of colors:
Bitmap or Black and White
It is the simplest color mode, since it only distinguishes between black and white, that is, between "nothing" and "something". This mode is valid only for text or for linear images, such as a pen drawing, but it would even be of little use for registering a pencil drawing, since it has shades of gray.
In this case we have 256 levels of gray between White and Black. It is, therefore, a suitable color space for Black and White photographs and for nuanced drawings. Also, having only one channel (the one in black) does not take up too much memory and is easy to handle.
It is a color mode that uses 256 different shades. It may be useful for some purposes, but overall 256 colors are too few to faithfully represent the real world. For this reason, this color mode is typically used only for simple illustrations, so it can be sufficient for many vector graphics. Some formats, like GIF, only work in this color space. The accompanying image shows how some areas appear very flat (such as the sky or the tree trunk) since there are not enough colors to represent all the nuances.
This is the most widely used format in digital media. It is made up of 256 shades in each channel: Red, Green and Blue. The result is that it can display millions of colors and faithfully represent almost every color in the real world. To the right of the RGB photo is the RGB color picker in Inkscape.
It is the color medium used by office printers and also by professional printers. It contains 100 shades of color in four channels: cyan, magenta, yellow and black. The first three channels provide the tonality and black contributes the intensity of the shadows, to enhance the images. The CMYK and RGB correspondence is not exact, especially in some very bright shades of greens, blues and oranges that RGB best represents, but in general they can be transformed with certain guarantees. In any case, it is necessary to remember that the RGB images that we see on the screen will always be more intense and vivid than the CMYK images on paper, since RGB has the advantage that the screen has its own light, while the inks of the paper are rather than reflecting the light that falls on them. If the final objective of our design is to print on paper, it would be preferable to choose the colors in Inkscape directly in CMYK, to avoid "surprises" when seeing the result.
It is a color system that is based on three parameters:
- H (Hue): Tone
- S (Saturation): Saturation
- L (Light): Light
It is quite intuitive, because first we choose the tone and then we deal with its saturation (how pure it is) and lightness (how dark or bright it is).
It works similarly to HSL. In the outer wheel we choose the tonality (the color) and then we vary in its purity and luminosity.
In Inkscape we can generate the colors in the Object> Fill and border menu, where a dialog appears that allows us to choose between RGB, HSL, CMYK and Color wheel. We can move both the handles and assign the colors in numbers. Keep in mind that in RGB and HSL colors move between 0 and 255. In RGB, black is 0.0.0 (absence of light) and white is 255, 255, 255 (total light). In CMYK, on the other hand, colors go by percentages of inks, from 0 to 100. White is 0, 0, 0, 0; and black is 100% black.