When choosing a color for a shape, text, background or other element in Book Creator, you have the option of choosing from a preset color, or using the color wheel to pick and color/brightness to select a color.
Now, you can also use a hex code to select the color. A hex code is a six-digit combination of letters and numbers that define its mix of red, green and blue (RGB) values. It is primarily used in web design as the quickest way of defining a color.
Using hex codes
You might want to use a service like this color picker from W3 Schools that shows you some common hex code values. In Book Creator,
Select the item (text box, shape, icon, page background etc) and click the Inspector (i button).
Click on the Color option in the menu.
You'll see a selection of preset colors, but you need to click on the blank one with the + symbol inside in the bottom right.
Enter the hex code in the area provided (note - hex codes always start with a # hashtag, but you won't need to enter that here, just the numbers).
Alternatively, you can choose any color in the color picker and it will update the hex code so you know what it is. This is great for matching colours throughout your book.
Matching the color of an image you've added
Sometimes you might have added an existing image to your book and you want to match a color from that image. With hex codes, this is much easier to do. I use a 3rd-party extension such as ColorZilla which provides an eye-dropper tool. You simply select the color you want with the eye-dropper, and it will tell you the hex code, which you can then enter using the method above.