In the following places, on page 1113, the highlighting of changes is incomplete:

1) First block of code on page:
  As well as:
oldCellBackColor = highlightedCell->Style->BackColor;

the next line should be hightlighted
oldCellForeColor = highlightedCell->Style->ForeColor;


2) In same block of code:
  As well as:
hightLightedCell->Style->BackColor = Color::White;

the next line should be hightlighted
highlightedCell->Style->ForeColor = Color::Black;


3) In next block of code:
  As well as:
highlightedCell->Style->BackColor = oldCellBackColor;

the next line should be hightlighted
highlightedCell->Style->ForeColor = oldCellForeColor;


4) In the code at the bottom of the page:
  As well as:
// Check whether the cell is highlighted

the next two lines should be hightlighted
if(dataGridView->Rows[e->RowIndex]->Cells[e->ColumnIndex] == highlightedCell)
return;