The main colour of the Protime brand is blue. There are three shades of blue available which you can combine. In addition, there's also yellow, green and red as secondary colours. Use those secondary colours with care.
Protime's secondary colours are green, yellow and red. You can (but are not obliged to) use an extra colour when formatting, in addition to the three shades of blue. You are only allowed to use one extra colour per document though for titles and blocks. So blues + green, blues + red or blues + yellow. Never use blues + red + green for instance. The colour restrictions do not apply to the icons. You can use any icon in your document, regardless of the colour of the icon.
In addition to the colours, there are also two shades of grey you can use to fill larger areas, or to use for silent text.