def METHOD_NAME(a, b, f):
    """Interpolate between two colors.
    Returns:
        `QColor` object.
    """
    a_ = (a.redF(), a.greenF(), a.blueF())
    b_ = (b.redF(), b.greenF(), b.blueF())
    a_ = [x * (1 - f) for x in a_]
    b_ = [x * f for x in b_]
    c = [x + y for x, y in zip(a_, b_)]
    return QtGui.QColor.fromRgbF(*c)