Here are some very plain but universal models - a single color background with some star dust splittered on it. You can use this standalone, or as a basis for customizations. For instance, you can use the Text tool to add your text.
I like working with colors and have always enjoyed these subtle shades that make a color look unique and so pleasing to the eye. I've tried to include many colors but since there are millions of them, it's obvious I can't include them all. The designs are split into categories based on the color they are a shade of: blue, brown, cyan, gray, green, orange, pink, red, violet, white, yellow. Some of the colors could go into more than one category because they have more than one main color in them, so don't be surprised when you find pinkish looking models in the red or violet category - from a technical point of view, they are more red/violet than pink, even though it doesn't look so.
If this plain model is too plain for you, you can browse the other designs in the shop - they use the same colors plus various subtle, unobtrusive effects. For more models, you can check my other shops - Tartan Plaid Designs
and Geometrical Shapes
, where you will find many tartans and plaids and designs with stripes, squares, circles, and other geometrical shapes, respectively.