The Steel Horned goes with it, due to the pattern, but the other looks out of place. I still think the dragonbone helmet looks fine with the rest of the armor.

The Steel Helmet looks good with Guard/Stormcloak Armour.

Thanks. It's too bad the shield doesn't really match.

Matter of opinion. It doesn't have to have the same exact pattern to match.

I think that there are 2 sets of steel armor. One is the steel nordic (kind of the wavy patterns; used by stormcloaks; steel horned helmet falls in this category), and the steel imperial (more blocky and shiny; used by imperials; steel helmet falls into this category). There are 4 peices to each set (head, chest, boots, gauntlets). I think you are mixing the two sets together, which could make it look wierd

Nope, steel plate has http://img2.wikia.nocookie.net/__cb20121023003254/elderscrolls/images/6/69/Steel_Plate_Helmet.png of helmet, "regular" steel has two helmets available, http://img2.wikia.nocookie.net/__cb20121024005755/elderscrolls/images/4/4d/Steel_Horned_Helmet.png and http://img1.wikia.nocookie.net/__cb20121024005750/elderscrolls/images/7/72/Steel_Helmet_SK.png. And I personally totally dislike the horned one.

I don't think the OP is talking about steel plate... and neither was I

Maybe you were talking about http://hydra-media.cursecdn.com/skyrim.gamepedia.com/thumb/f/f2/NordicCarvedHelmet.png/200px-NordicCarvedHelmet.png?version=ab5e06e38dfa854b336651845b212315, but regardless of that, OP was not talking about steel plate or nordic carved, he was talking about regular steel which is the only steel set that offers two helmets and only steel set which offers a horned helmet.

I wasn't talking about steel plate or nordic carved. I was talking about regular steel armor that you get when you unlock the very first perk in the smithing tree. If you noticed in game, there are 2 armor sets (both with the same AR) that look slightly different.

Steel imperial: http://img4.wikia.nocookie.net/__cb20121017150910/elderscrolls/images/thumb/3/3d/Imperial_Bracers1.png/200px-Imperial_Bracers1.png, http://img1.wikia.nocookie.net/__cb20121017150907/elderscrolls/images/thumb/d/d7/Imperial_Boots1.png/150px-Imperial_Boots1.png, http://img1.wikia.nocookie.net/__cb20121024005750/elderscrolls/images/thumb/7/72/Steel_Helmet_SK.png/200px-Steel_Helmet_SK.png,http://img2.wikia.nocookie.net/__cb20121027202850/elderscrolls/images/thumb/d/d5/Steel_Armor_Paldrons.png/1000px-Steel_Armor_Paldrons.png

Steel nordic: http://img4.wikia.nocookie.net/__cb20121024005816/elderscrolls/images/thumb/2/27/Steel_Nordic_Gauntlets.png/170px-Steel_Nordic_Gauntlets.png, http://img2.wikia.nocookie.net/__cb20121024005733/elderscrolls/images/thumb/e/e8/Steel_Cuffed_Boots.png/120px-Steel_Cuffed_Boots.png, http://img2.wikia.nocookie.net/__cb20121024005755/elderscrolls/images/thumb/4/4d/Steel_Horned_Helmet.png/250px-Steel_Horned_Helmet.png, http://images.wikia.com/elderscrolls/images/archive/6/6f/20121027202844!Steel_Armor_No-Paldrons.png

Same armor rating, but imperial set is still a completely different set unrelated to the regular steel one, and also doesn't offer a horned helmet.

U don't make any sense good sir. I never said that the STEEL imperial set offered a horned helmet. Just admit you're wrong and we can get on with our lives . There are 2 different LOOKING armors in the steel category (regular 1st teir steel). The Nordic set (as seen in my other post) and the imperial set (as seen in my other post). I included pictures and everything. They look different, but are still classified as steel. All I was saying is that the OP might have been using the regular steel helmet on the steel nordic set, so it wouldn't match

You can just imagine 2 hardened barbarians standing in an armoury can't you:

1st barbarian: Do you think this helmet is really me?

2nd barbarian: Ooh, I really don't know, try the pink one I think it goes more with your boots!

1st barbarian: Stop taking the piss, I'm goin to buy the Stalhrim headpiece and that's that!

Actually , the imperial steel curiass is http://img1.wikia.nocookie.net/__cb20121017150919/elderscrolls/images/c/c3/Imperial_Cuirass.png and the imperial helmet is http://hydra-media.cursecdn.com/skyrim.gamepedia.com/thumb/f/f6/ImperialOfficersHelmet.png/200px-ImperialOfficersHelmet.png?version=75483ec09acdc09d2feb4075ab7f1687 the items you listed as the imperial steel armor and helmet are variations of the steel nordic armor.