I created some customized toolbars in Excel, and I'd like
to change the appearance of the buttons (background color,
font size, bold) so that it would stand out compared to
the regular Excel toolbars, can anybody tell me how to do
it? Below you'll find my code:

Set metricsbar = CommandBars.Add(Temporary:=True)
With metricsbar
.Name = "Metrics"
.Position = msoBarTop
.Visible = True
End With

Dim clearbutton As CommandBarControl
Set clearbutton = metricsbar.Controls.Add
(Type:=msoControlButton)
With clearbutton
.OnAction = "Clear_AIMSOutput"
.Caption = "Clear AIMS Output"
.Style = msoButtonCaption
End With

Thanks,
Alex.