in Delphi's DBGrid :: 
You've seen this surely on web pages. Alternating table row colors means displaying the first record in one color and the second record in another color and continue to alternate the color of each row displayed.
You've seen this surely on web pages. Alternating table row colors means displaying the first record in one color and the second record in another color and continue to alternate the color of each row displayed.
When working with datasets with many rows, alternating the background color of each row can increase readability.
Read the full article to learn how to Alternate DBGrid Row Color.
Related:
When you have long lines, the problem is still there.
Grouping the grid or report in 3 lines at a time (instead of alternating every line) makes it much easier to read, especially when dealing with long lines.
One problem with this solution: RecNo may not be correct when dataset is filtered.