There will be times when you want to easily display a dashboard message for a client in wp-admin. An example of why you would want to have a specific dashboard message display would be to remind a client about a change or a new feature that was added to the site. The easiest way to achieve this is to use the WP Dashboard Messages plugin.
Once the plugin has been installed and activated it will add a new admin menu;
Dashboard Messages > Add New
When creating a dashboard message you can select the color scheme it uses, the layout of where it will display, and if the message will expire options or if you want the dashboard message to be dismissible. You can select an icon that uses the Dashicons in WordPress to display in the dashboard message.
You can view all of the created dashboard messages from;
Dashboard Messages > All Messages
You can use one of the filters in the plugin to add custom color schemes to the dashboard message plugin.
Using the WP Dashboard Messages plugin will make it very easy to create any dashboard messages for clients when needed.