In general, Outlook categories consist of a name and an associated color. If an Outlook item (for example, an e-mail or a contact) is assigned a category, then Outlook stores the name of the assigned category directly in the element. The assignment of a respective color is not stored in the element, but in a separate reference list i.e. category list. Since SYNCING.NET can only sync the Outlook items, the category name will be transferred to the element, but not the color assignment.
On the computer where the changed Outlook item in received, a local category list will appear without the color assignment but as a new category (in Outlook 2010 under Start -> Categorize -> All categories). If you click on this category with the left mouse button highlighting the item, and click on "New"; “Add a new category" will appear allowing you to add color on the already existing name from the other computer which will also be appearing on this PC without color assignment (assign color). Thereafter, this category is automatically available in the future.