Updating Dataset with Removed Columns

Hi everyone!

I have been working with Power BI for just about a month now but am having some difficulties with updating my data. When I originally uploaded my table, it had 9 columns:

.
Since Grey and Orange were never the correct colours to be used, I deleted them from the file. So now, the document appears as:

 .

But now when I'm trying to refresh the data, even though the columns Orange and Purple were empty, I'm getting an error that says
"Expression.Error: The column 'Orange' of the table wasn't found."

Is there any way I can still update the data even though the original data had the extra columns? It would be a pain to have to manually add the columns Orange and Grey every time I wanted to refresh my data. 

Thanks!

UPDATE: The reason it said Expression.Error is because it was still trying to change the type of Orange and Grey, so I just modified the "Chahnged Type" Step. The new Error is:

"Failed to save modifications to the server. Error returned: 'Column 'Year for Seller' in the table 'Colour Sellers' cannot be found or may not be used in this expression. An unexpected error occured (file 'tmtransactioin.cpp', line #, function 'TMTransaction::GetProxyFromPrevSavePoint').' However, I don't have any measures or calculated columns that are related to this column in the other table at all, and the 'Colour Sellers' table is no longer there.