If you want to provide yourself and your co-workers with a messenger in your organisation’s colours, you can set a colour theme.
Company admins can access the company settings by going to the menu in the top right corner of the web version and then clicking ‘Company settings’. In the company settings, go to the ‘Theme’ tab.
Here you can pick different colours for different parts of the messenger. When you click “Save theme” the theme will be changed for you and your companies employees. Your business contacts will not get your theme, this is only for your companies employees.
Tip: use a so-called colour picker to find out what exact colours are used in your organisation’s logo / website! Such a colour picker can be found in most image editing software (like Photoshop or free web tools such as Pixlr).