TriFill is a simple, relatively constrained coloring activity. Despite its simplicity it provides ample opportunity for creativity, exploration of symmetry and color harmony. Anyone from a young child with basic mouse skills to an adult looking for a relaxing pastime can find enjoyment with TriFill.

Things You Can Do How To Do Them
Select a color Use the Color Spelunker on the left to pick a color. See the Color Spelunker instructions for more details.
Color a triangle Enable coloring by clicking (coloring is initially enabled). Then click within any triangle to fill it with the current color.
Erase a triangle Click any triangle with the right mouse button instead of the left.
Change the background color With coloring enabled and the desired color selected, click in the area just outside the triangles.
Get the color from a triangle Enable color pick-up by clicking then click the triangle of interest.
Select a group or triangles Enable selection by clicking . With the mouse positioned slightly above and to the left of the triangles you want to select, press the mouse button then drag down and to the right. Release the mouse when the selection marquee surrounds the desired triangles.
Move selected triangle colors Move the mouse inside the selection outline, press, drag to the desired location and release. Preexisting triangle colors at the release location will be overwritten.
Copy selected triangle colors There are two ways to copy.

  1. Follow the Move instructions above while holding down the Ctrl key
  2. Click any of the four directional copy buttons
Flip or rotate selected triangle colors Click on any of the flip or rotate buttons. Flip and rotate are only enabled for square selections.
Change the number of triangles Click the up or down arrow adjacent to the “Count” value appearing above the main drawing area.
Undo changes Click to undo the last change (color, erase, move, copy, flip, rotate or triangle count change). Click it repeatedly to undo multiple changes.
Redo changes Click to redo the most recently undone change.
Start a new drawing Click¬† to start a new drawing. If the current drawing hasn’t been saved you will be asked whether to save or discard it.
Replay activity Click to replay the entire series of changes that led from a blank canvas to the current drawing.
Save a drawing
(Not available on Mac)
Click to save the current drawing. Saved drawings appear in the collapsible area at the bottom of TriFill. You can also save the current drawing by clicking the that appears next to its thumbnail in the saved drawing area. Drawings are saved locally on your computer and will appear anytime you return to the TriFill page.
Export a drawing
(Not available on Mac)
To export a drawing to a file of your choosing, select the drawing by clicking its thumbnail in the Saved Drawings area then click at the right of the area. Choose a location and file name in the dialog that appears. The drawing will be saved in PNG (Portable Network Graphics) format.
View previously saved drawings Click on any saved drawing to see it full size in the main display area.