Thanks for contacting Syncfusion Support.
We have checked your query and we were not able to reproduce the reported issues in 220.127.116.11 version of assemblies. Could you please confirm us, in which version of assemblies the issues were reproduced?
We have prepared a sample based on your queries and the background color is maintained properly after unhidden the column. You can download the sample from the below link for your reference.
If you still facing the issues, please do revert us with modified sample reproducing the issues which will help us proceed further.