To begin this section, we can say that the colours we see are not something themselves: they are a subjective perception that only exist in our brain. The colours we see in the objects are the result of the stimulation of the optic nerve through white light waves of different lengths which are reflected by these in a certain moment. Every object reflects a certain amount of white light and absorbs the rest, and from there they obtain their colour.
As regards design, we can mention two big groups of images: colour images and black and white images. In this section, we will discuss colour designs and how these must be worked. Colours, as every perception, are carriers of meaning, and we must be aware of that in order to design an effective corporate logotype. Obviously, there is no such a thing as a table of colours with their respective meaning. However, there are certain cultural conventions and psychological studies which give us an approximate meaning for the common of people. The colours applied to the Logo can transmit sensations, such as: warmth, e.g.: red shades; coldness or asepsis, e.g.: blue shades; strength, e.g.: black; etc. You will select the colours of your corporate Logo, but it would be convenient to consult other designers and experts in marketing about the advantages of using a colour instead of other.
Colours carry meanings and create emotions, yet they do not do it as words do it. Many times consumers feel especially attracted to a product without knowing why. This happens since consumers subconsciously incorporate the meaning that the colour transmits: they do not know why they consider a product more pleasant than other by just looking at it. And in the same way that this happens in a supermarket with the labels of the products which are displayed, the same happens with corporate Logos in the general market.

There are two ways to compose colour: the harmonic and the contrasting. The harmonic composition is the one that uses modulations of a same shade or of different shades and keep the same pigments among them. Harmony consists in the combination of three colours: the dominant, the tonic and the mediatic. The dominant is the one that has a greater percentage, the more neutral and the most prominent. The tonic is the most powerful as regards colour and the one with higher values. Finally, the mediatic acts as a transition between the other two. The latter is usually used to modify the sensation that colour produces directing it to one or other direction. The simplest one of the harmonic chromatic combinations is that one that fuses the shades of the same range. On the contrary, the contrasting chromatic combinations are those that gather colours of different range and that have nothing in common.

When you have to choose the colour of your logotype, it will be very important that you have in mind the difference between RGB and CMYK colours. RGB colours are those reproduced by monitors or video screens, and which are obtained by combining red, green and blue. CMYK colours are those reproduced by the printers of the printing houses, and are obtained by combining cyan, magenta, yellow and black. It is important that you know this distinction since if you choose the colour of your logotype from a Web page or from a RGB colour palette, that colour will be reproduced in an identical way in those places where the reproduction of colours is done through the RGB model (that is to say, on the Web page, on television, etc.). The chosen colour from the RGB palette cannot be identically printed on the graphic media or, say, on the uniforms of your company personnel. That is why unless you ask for a logotype to be used only for your Web site and for TV commercials, the designer will have to convert the colour to the CMYK model that you have chosen from the RGB palette. This conversion is done because the RGB colour palette is wider than that of the CMYK and many of those colours in the first palette are not in the second one. The designer of your corporate Logo must transform those RGB colours that you have chosen to CMYK colours so that your Logo can be printed on graphic media, on the uniforms, on your personal cards, etc. By turning from a RGB colour to a CMYK colour this one can be kept similarly or be modified depending on the colour you had chosen. In any case, this should not be an obstacle: even great corporations have slight variations in their logotype’s colours. McDonald’s yellow colour is not always the same.