If you want to create tags to mark bookings you can go to:

Planning -->  Resrvations --> Occupation tags.

To add a new tag press on "New", to edit created tags press onand if you want to remove.

When you press on "New" you will see the next screen where you have to fill the tag name and the tag colour.

Press on Colour field and you will see the next screen:

You can move your mouse on the palette to select the colour you like for the tag and when the colour is selected press on to take.

To see where your created tags are shown, you can go to booking grid.

As an example, create a new booking. The bookings screen will be shown, where you will see the tags you have created in the upper right corner and you can select too.

You will have a caption in the lower left corner with the tag name and the tag colour. This tag colour will also appear on the bookings grid.