Nickel tends to be more yellow than normal mild steel. I would suggest that you try a different finishing method. Blasting will give a different look than brushing, which will be different than polishing, etc.
If you have already sand blasted it, try brushing it with a heavy duty abrasive pad, like Scotchbrite or similar. Note that the pads you find at the grocery store probably won't work, you may need to go to a hardware store to pick up the more industrial grades. You can also try using a different media in your sand blaster, like aluminum oxide or a more exotic material. Or try a finer or coarser grade.
You will also change the look of it somewhat by applying a wax, oil, or laquer. Test a small area and see how it looks. Since the material is steel, expect it to require frequent touchups or rust may begin to show through, especially with a wax or oil coating.
From a chemical perspective, they make several types of antiquing chemicals for steel. These chemicals will darken the metal. Most of them are fairly dangerous, and should not be used without the correct permits and knowledge. Look around in your area for somebody that does black oxide or gun blueing. You may be able to have them darken your entire desk, which you can then try to partially remove to create a darker steel look.
-Dustin Gebhardt,
CEF
Plating Engineer
Danaher Tool Group
Gastonia, NC
