Hi Chris,
We have checked your query "Changing of background color when it is editable" on our side. We could not able reproduce the issue from our side. The background color was changed properly in the SfComboBox control.
We have shared the sample in the attachments. Can you please explain if you need to change the full background on the control or only the editable area of the SfComboBox? Based on that we will check and share the details.
Regards,
Shivani
Attachment:
ComboBoxSample_d391b2f6.zip