Eye-catching colors

Not all colors are as eye-catching as others. This can cause a problem for data visualization, because having some data point more obvious than others can bias the way you interpret a plot. Unless you specifically want to highlight some points, each data point should be as easy to look at as all the others.

Here you can see the dataset from the camera trap in Panama. This time, the speed of the animal as they passed the camera is plotted against the time of day that they were caught on camera, and the agouti have been joined by another rodent, the paca.

Each version of the plot contains purple and yellow points, but in one version, the purple points are easier to perceive than the yellow points.

Which statement is true?