1. Psychology and representation
There are several colours and each of them symbolise different emotions. But there are some commonly accepted colour association like red colour is used to show danger while green is used to display safety. This is main reason why green is preferred to display nature, youth & money related designs, whereas on the other hand red is used to highlight caution or things that need attention. Dark blue is usually used to signify trustworthiness & safety, while pink & light purple stand for femininity. But dark purple is used to represent luxury. Nevertheless, it will be your creativity and experience which will guide you to choose a colour theme.
2. Know your target audience
Who is going to see your ad will also help you in selection of colour theme. The best thing is you can create two versions of the same design with different colour themes so that you can attract people across geographies & cultures. For example, in the Western countries red symbolizes passion, danger or risk. So, you can to use it for social awareness or love stories related designs. Whereas, in South Asian countries red represents wealth. So, you can use red in your festivities & prosperity designs. Always ask some important questions before starting your designing work like about the demographics (age, gender, cultures, etc.). Subsequently, you don't want to choose a colour theme that can be misinterpreted for some reason.
3. Take help from the given source
At the time of complete loss, take help from the already existing source material. This will consist of a company logo or some other branding material. It will also support you choose a colour theme. For example, in the case of McDonald's, it is always recognised by the big yellow M against the red background. And it is best to follow these colour variations for better brand recall & impact. But that does not mean that everything related to them should be made in red & yellow. Use these colours as the starting point, and explore various options till you find the right colour combination.
4. Stick to three primary colors
At times you may be tempted to use a lot of colours, but it is advisable that colours should be used in moderation. Always try to choose a colour theme that make best impact. The best solution is to have one dominating colour, with one or two other colours to complement it. In case you feel that there is a need of using more colours, make sure that they are used only when required & do not outshine everything else. If you need any kind of information on this article-related topic click here graphic design
5. Use of shades and tints
Apart from choosing the primary colours, if you require any additional colours, then make use of shades and tints. It can be easily attained by adding black (for a shade) or white (for a tint) to the main colour. Using them will make the whole design look as one without making it look boring.
6. Experiment to create unique designs
In many instances, it may be best not to stick to the rules and try something different. Once you have understood the basics, there is no harm in experimenting to create something striking designs. It will lead to invention of new designs. Use those colour combinations that would usually not be used together.