The array is in a format that can be directly used in BaseChart.gradientColor2 and DrawArea.gradientColor2. Its contents (in hex) is:
00 C8C8C8 60 F8F8F8 B0 E0E0E0 100 C8C8C8
See Color Specification on how colors are represented in ChartDirector.
ChartDirector 7.0 (Perl Edition)
perlchartdir.
Description
00 C8C8C8 60 F8F8F8 B0 E0E0E0 100 C8C8C8