I've been spending quite a bit of time trying a free quilt designing program for Windows PCs. Quilt Assistant is primarily planned for creating quilts from photos and drafting traditional blocks. However, hidden away is the computer equivalent of colouring pens and paper for designing quilts made up of a single shape such as squares, hexagons, triangles, and many more.
The online manual shows how to create quilts from photos and how to design traditional quilt blocks but it doesn't mention this other very useful design feature, so I've put together a few screen shots to get you started.
The single shape design feature can be accessed by clicking the “regular pattern” tab when creating a new blank project (the default tab is “free design”).
This tab allows you can choose your shape (or pattern) and adjust the size and count to create a workspace representative of the finished size of your quilt. The default setting is for squares, but there are several more exciting shapes available including clamshells and applecores.
In the workspace, you need be in “coloring mode” (the grid lines will be solid and a color selection palette will appear). This can be selected by the button in the upper right of the screen or from the "Mode" drop down menu.
Then it is just a matter of using the mouse to select colours, fill in the shapes and create your quilt design. There isn’t an eraser as such - if you make a mistake you recolour the shape using the correct colour or the background colour.
I've not tried using the program for its primary purposes of designing picture quilts or traditional blocks, but I've found it to be great for this type of designing, especially for hexagon quilts. It doesn't have advanced features such as pattern fills or importing jpg files of fabrics, but it is a lot easier than using pens and paper. The program is free from cosman.nl and while the author was at one time accepting quilt fabric in lieu of donations, this is no longer the case.