Assuming you're referring to autoshapes, all of this is possible with VBA but, without knowing precisely what you want to change, it's impossible to supply the code. As a demo:
Code:
Sub Demo()
With ActiveDocument.Shapes(1)
.AutoShapeType = msoShapeOval 'msoShapeRectangle
.Fill.ForeColor.RGB = RGB(255, 255, 0)
.Fill.BackColor.RGB = RGB(127, 0, 0)
.Fill.TwoColorGradient msoGradientFromCenter, 2
.Fill.Transparency = 0.25
.Line.Weight = 2
.Height = InchesToPoints(1.25)
.Width = InchesToPoints(1.5)
End With
End Sub