Logo in Sap Script

Guys

My client is using SAP 4.7. I want to make voucher printing through SAP Script - Correspondence. I have performed all the customisation however when I put the logo in the voucher, the logo is coming with grey background.

The Logo which I have put in the SE78 is proper logo with white background. But when I print the correspondence it is showing Grey background. I have seen the standard SAP logo it is coming with White Background why my company is getting grey background.

Can you please tell me how to rectify this issue.

Thanks

SH