Start with the sunset color blend or any color you would like for the canyon walls.
Divide the blend into two parts.
Stack the smaller part like this.
Mix a very, very light yellow. You may be able to use a tiny bit of the lightest part of your cane mixed with white. Flatten and stretch the light clay so thin that in begins to tear. Slice into the block and add little pieces of the light clay.
Keep going until you get close to the top. For the last three sections cut a little off the ends and re-attach it. Then slice another section a little higher from what is left and cut even more from the ends. Finally there will be a stair-step line for the water. Cover each layer with light clay. These are the sparkles of light on the water.
Now for the canyon walls! The idea is to show the layers of sandstone with slight variation within each layer. Cut the remaining blend into four parts and roll them into balls.
Roll the balls into logs and flatten them into fat ribbons. Slice up the ribbons and stack them into blocks.
Cut the darkest block into two pieces. These are the canyon walls in the foreground. The light in coming in from the background, so each part of the canyon gets lighter as you more into the canyon.
I chose to show only one wall with the light colored block. The very last of the light in the background is the rest of the light color that I used as sparkles on the water.
This could also be done with blue to make sky instead of pure light. It can also look good to cover the cane in sheets of clay as a border.
This cane was inspired by this painting lesson, but wow there are some gorgeous pictures of slot canyons online if you just do an image search. Now that you know how to make the variegated lines, imagine the beautiful variations!