To easily recognize data items belonging to the same category, it helps to have:

1. a good qualitative color palette, and
2. a consistent use of that palette for charts on that page.

This is why I wrote two corresponding How-To articles:

1. Add color palettes
   This article is about using qualitative color palettes that can be obtained from the internet, and subsequently transcribed to a CSS file that can be used in conjunction with annotations for AIMMS Data Dependent Styling.
   This article comes with an AIMMS application that let you transcribe your own palettes.
2. Consistent data coloring on an AIMMS WebUI page
   This article is about using the CSS files created in the first article to obtain a consistent use of the legend for all widgets on that page as shown in the following picture:

   

I hope these articles will help you in setting up data visualization palettes for your own application.