复制下面代码粘贴到子窗体中你会看到很好的效果：（项目ID要改为你表或查询中的ID，如代码ID、KHID）

Private Sub Form_Current()

Dim ctl As Control
For Each ctl In Me
    If ctl.ControlType = acTextBox Then
        ctl.FormatConditions(0).Modify acExpression, , "[项目ID]=" & Nz([项目ID], -1)
    End If
Next ctl
End Sub

Private Sub Form_Open(Cancel As Integer)
Dim ctl As Control

For Each ctl In Me
    If ctl.ControlType = acTextBox Then
        ctl.FormatConditions.Delete
        ctl.FormatConditions.Add acExpression, , "[项目ID] = -1"
        ctl.FormatConditions(0).BackColor = vbBlue
        ctl.FormatConditions(0).ForeColor = vbWhite
    End If
Next ctl
End Sub