One interesting first birthday party theme would be the rainbow party. As the name suggests, this theme will be based on various colors which will be largely revealed through your party decorations. The theme should start with rainbow colored invitations. 

These can be found at your local party supply store or stationary store. You can also mix and match solid colored streamers and balloons to decorate the party space. You also mix and match solid colored paper products such as plates, cups, and napkins for the party. You can contact with party organizer for Unique and Reasonable Spa Party in Ajax.

Kids really enjoy birthday party themes because they get to dress up as their favorite superhero or villain and you can also invite a person to dress up in a costume of the character that the birthday kid likes the most.

If the party is for a grown up then you can have a theme such as of olden times or for example one where the birthday girl or boy is the prince or princess and on the invitation, you tell people that you are inviting them to your ball but they have to wear masks. This kind of mysterious party will definitely be a big hit. When looking to create a birthday party theme it is important to keep to a certain standard and do not go overboard lest you lose your theme.