Export Data Store Entity to Excel - Excel file column wrap and header row color

Well yes there is a way.

For that, you need to create an excel template in which you will add the headers manually (all the fields of entity in the same order as in generated document) and color you want in the header row and format the wrapping of desired columns. Then upload that document in the appian folder.

Now when you are using Export DSE to Excel service you will provide this template document in documentToUpdate input and save this node input in a pv say pv!docTemplate and for startingCell provide "A2" and set IncludeHeader to false. Note that you will not be able to create new document now but the new version of this same document will be created and the name will also be same.

Now use Copy Document smart service to copy the generated document from above (node output) with a new name which you wanted from your actual generated document and then save the generated document from this service in the same pv! which your provided in input

And then use Delete Document Version smart service to delete the new version that was created in Export DSE to Excel SS, this time use the pv!docTemplate to pass value in Document input (keep versionNumber empty, it will delete the latest version). This step is necessary as we need to delete the new version so that we can have our Excel template back which will be used next time.

Now, call this process model in saveInto of your Generate Document interface component using a!startProcess and onSuccess save the value of pv in which you saved the output of Copy Document SS in a local variable and at last use this localVar in documentDownloadLink to download the document.

Example code:

a!localVariables(
  local!generatedDocument,
  {
    a!buttonArrayLayout(
      buttons: a!buttonWidget(
        label: "Generate Document",
        saveInto: {
          a!startProcess(
            processModel: cons!PA_Export_DSE_TO_EXCEL,
            onSuccess: a!save(
              local!generatedDocument,
              fv!processInfo.pv.NewDocument
            )
          )
        }
      ),
      align: "START"
    ),
    a!linkField(
      links: a!documentDownloadLink(document: local!generatedDocument, label: "Download Doc" )
    )
  }
)

edit: Have a look at the comments below and change this approach slightly by copying the document template first and then just use that copied document in Export DSE to Excel SS.