Here's a macro to change the colour of characters in the selected cells.
Sub ChangeBlueToSpecificColor()
Dim rng As Range
Dim cell As Range
Set rng = Selection
If rng Is Nothing Then
MsgBox "Please select a range of cells first.", vbExclamation
Exit Sub ' Exit the macro if no range is selected
End If
For Each cell In rng
For i = 1 To Len(cell)
If cell.Characters(i, 1).Font.Color = RGB(15, 158, 213) Then
cell.Characters(i, 1).Font.Color = RGB(0, 0, 255)
End If
Next i
Next cell
End Sub