Common Problem while using windows.print() is that the background colors for table cells not printing
If you’re using IE, that behavior is controlled by user’s settings, Please follow the following steps
The Print background colors and images setting from the Advanced Tab of the Internet Explorers Tools, Internet options pane does not adjust the Print background colors and images setting of the Page Setup options in Internet Explorer 8.
To work around this issue, verify that the Print background colors and images setting in the Page Setup settings is set correct. To do this, follow these steps:
 In Internet Explorer 8 click File from the menu and click Page Setup
 On the Page Setup dialog box ensure that the Print background colors and images setting is checked.
Click OK to close the Page Setup window and print your page again