The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change gradually from red at the left to green at the right (through yellow in the middle).

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change gradually from green at the left to blue at the right (through aqua in the middle).

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change gradually from blue at the left to red at the right (through fuchsia in the middle).

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in two steps from nearly gray at the left to red at the right.

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in two steps from nearly gray at the left to yellow at the right.

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in two steps from nearly gray at the left to green at the right.

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in two steps from nearly gray at the left to aqua at the right.

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in two steps from nearly gray at the left to blue at the right.

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in two steps from nearly gray at the left to fuchsia at the right.

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in ten steps from black at the left to white at the right with red at the middle.

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in ten steps from black at the left to white at the right with yellow at the middle.

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in ten steps from black at the left to white at the right with green at the middle.

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in ten steps from black at the left to white at the right with aqua at the middle.

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in ten steps from black at the left to white at the right with blue at the middle.

The following two matching (except the checkerboard at both ends to show where the rows are) rows of colors should change in ten steps from black at the left to white at the right with fuchsia at the middle.