After entering my custom colour it is shown at the bottom of the window in the Recent Colors, so I can quickly select it. However, when I close and reopen Word, my custom colour has gone. I have to enter the custom colour every time I start Word. It's the same story for the other Office applications.
I would like to have my custom colour available for all new documents I create. This can be very important, imagine your company has it's own corporate colours, shouldn't they be available to everyone as part of the standard colour palette? It's a bit much to expect user to enter custom colours using RGB codes for every document. Having the colours available easily will make the adoption of the correct colours much easier.
NOTE: I'm using Office 2013 / Word 2013 in my example here, in other versions you may find some differences but I hope at least this will help you find your way.
Solution for Word 2013
In Word, click File, New and Blank Page (or the template you would like to add your custom colour to)
Hover the pointer over Colors to see which theme you are currently using - as in the example below:
In the above example I am currently using the Office theme.
Click Customize Colors (at the bottom of the drop-down list)
On the ‘Create New Theme Colors’ window, select one of the preset colours, in my example I will change Accent 5 because it is already close to the custom colour I want to add.
Click the Custom tab
Enter the colour you would like, in my example RGB 0, 114, 188
In the Name box change Custom 1 to the theme name that you’d like, in my example “Corporate Colours” and click Save.
Now your new colour is accessible for the current document (you can see it at the top of the menu - above). However, if you’d like it to be available for all new documents using this template, on the Design tab...
...and click Set as Default.
Here's what it looks like to actually use it:
Once you've created a new Colour Theme in one Office application, it'll show up in other applications. For example, when I am composing an e-mail the same colours will be available. In the screen shot below you can see the Options menu where the Colors menu is located.
As with Outlook, the same is true but look on the Page Layout tab for the Colors option.
It is a little different here, go to the Design tab. Click the expand button on the 'Variants' box:
There is the usual Colors option to select from.
Deploy to other computers
I am sorry but I have not done this myself so I cannot provide a full explanation here. However, I did discover that the new Colour Theme I created and named "Corporate Colours" in Word, was stored as an XML file like this:
C:\Users\<username>\AppData\Roaming\Microsoft\Templates\Document Themes\Theme Colors\Corporate Colours.xml
I copied the Corporate Colours.xml file to the same folder on another computer with Office 2013. I opened Word, clicked Design, looked on the Colors button and yes, my Corporate Colours option was there at the top of the list. This means you could distribute this file to all workstations on your network to provide the corporate colours to everyone.
I also found the following page on the subject, using Group Policies:
I hope that helps!
If you are using a particular colour often, this really is a great little time saver. If you are using a whole palette of colours, perhaps a corporate colour scheme - this is essential. I say essential because expecting users to enter RGB numbers is a lot to ask them. They will make mistakes or forget. Customising the colours available in Office applications is best and as you can see here, it is not difficult.
Microsoft Office Change a Theme