To begin customizing up your platform's color theme, click on the Settings button in the upper-right, then on Branding and Customization.
Click on the Theme Customization tab to select a theme you would like to edit.
You can click on the Preset Themes button to access preset color themes as well as any that you save.
If you want more granular control, scroll down to customize the colors yourself. You will see several sections, with one for the Navigation Bar, Buttons, Section Headers & Tabs, Icons & Links, and Course Partitions. Just click on the color button to open the color picker.
On the color picker, you can click on the palette to select the color you want and drag the slider to change the selected hue. You can also directly enter the color information below the slider. Clicking on the default RGB (Red Green Blue) text will let you switch to HSL (Hue Saturation Luminance) and Hexcode modes, allowing you to precisely select which colors you will use.
The preview will be updated live, so you can see what your platform will look like before you commit to a theme. When you're satisfied, click the Update Branding button at the bottom of your screen.
Then head to Dashboard Cusomtization under Platform Settings.
Here you can select the Dashboard you would like to edit.
Here you are able to apply a theme you have created and save the changes to your dashboard.