The effect of the B&W 58mm 040 Yellow-Orange (16) Filter is quite powerful. It darkens violet and blue very strongly. It even darkens yellow-green a bit. Landscape and architectural photographs have an increased, virtually "graphic" contrast.
More dramatic effects are possible with orange filters with clouds starting to jump off the print when photographed against a clear blue sky. It should be noted that if orange still does not produce the desired effect, a red filter will give maximum boost to your contrast. And, if a polarizer is used in conjunction with these filters, the effect of a threatening storm can be achieved.
Reviews B+W 58mm 040 Yellow-Orange Glass (16) Filter