You can use any of the contextual classes to only add a color to the table header:
| Firstname | Lastname | |
|---|---|---|
| John | Doe | john@example.com |
| Mary | Moe | mary@example.com |
| July | Dooley | july@example.com |
| Firstname | Lastname | |
|---|---|---|
| John | Doe | john@example.com |
| Mary | Moe | mary@example.com |
| July | Dooley | july@example.com |