Coloris is a simple puzzle game based off the altering of different shades of color. The most basic puzzle has four shades of color, while one that's more advanced could have nine.
The shades are important because they allow you to solve the puzzle. The most basic puzzle is a 5x5 grid which contains blocks, each one colored one of the four shades. Pressing A over a block will change that color to the next shade based on the color of your cursor. If the cursor is dark, it will change to the next darker color, while if it's light it will change to the next lighter color. If it is already at the darkest or lightest shade, depending, it will remain the same color and not cycle around.
The purpose of changing a color is to get three or more of the same shade in a row. This will clear those blocks, and either score you points or a meter at the top will fill up, depending on what mode you're playing.
Once you get into more advanced puzzles, there will be multiple color schemes. If your cursor is of the wrong color scheme and you try to change a tile of another, it will turn black. These black tiles must be cleared by clearing blocks around them or else you will be unable to fill up your meter.
Sometimes special blocks will appear. For example, one with an X on it. If this block is cleared, all blocks diagonally from that X block will be cleared as well, filling up your meter faster. There is also a block which has a pulsing white block inside. Clear this block and all blocks with that color will disappear.
There are two modes, Clear and Score. Clear has a meter which you must fill up to allow you to move on to the next stage and unlock that puzzle. Score contains the unlocked puzzle colors from Clear, but the stages are now unlimited in length and allow you to score points.
Although Coloris is a Japan only release, the game is completely in English. The manual, however, is not.