You could choose you shading color and create a couple of macros to
easily apply and remove it from selected text:

Sub ApplyMyShade()
Dim oRng As Word.Range
Set oRng = Selection.Range
oRng.Shading.BackgroundPatternColor = wdColorLightTurquoise
End Sub

Sub RemoveMyShade()
Dim oRng As Word.Range
Set oRng = Selection.Range
oRng.Shading.BackgroundPatternColor = wdColorAutomatic
End Sub