I've noticed a lot of authors have this, so it is safe to assume I probably should as well.

Disclaimer: Hetalia and its characters are not mine.

Attributes and Characteristics

The first had a pale complexion.
One that winter frosted with creamy vanilla
and summer melted into light amber.
Skin that was touched by the hues of peaches
A master work of milky tints.

The second had an infinite tan.
One that autumn painted with rosy gold
and spring darkened into soft caramel.
Skin that sported the burnt touch of maroon orchids
A master work of ruddy tones.

When they stood next to each other, heads tilted in thought
it was like seeing corn silk and honey
Set side by side on a blank canvas.
It was comparing rolling waves of summer wheat
to burning flames of candles at night
Goldenrods and dandelions to
butter flowers and evening primroses.
In winter one is vibrant; the other, luminous.
In summer, the colors flipped;
one was bleached almost white under unrelenting heat,
the other burnished to gold under warming rays.
No matter what though, it was always, always
seeing amber pressed to ash blonde.

One has violet eyes.
Eyes the color of hazy mountains,
the color of the soft twilight sky,
the color of glittering amethysts,
the color of rustling lavender,
and depending on the circumstances, they could also be
the color of royal satin fashioned for a king.
Endless depths of a thousand different varieties of violet.

The other has blue eyes.
Eyes the color of the ocean,
the color of the clear summer sky,
the color of glowing sapphires,
the color of arctic ice,
and depending on the circumstances, they could also be
The color of ever-changing eerie blue smoke.
Endless depths of a thousand different shades of blue.

One has a loud, booming laugh and voice
Brash behavior, confident strides
He wants to know everything and has a hero complex,
head always held high, even if
the world thought him wrong.
Self-centered, independent
He had fought for and earned everything for himself;
sometimes to the expense of others.
But he is genuinely sweet to those he cares about
though he doesn't understand romance well at all.
Ever giving support,
He has an innate desire to help others out.
Even if most of the time they argued
and squabbled over his nosy antics.
However, he was born in blood; raised through wars
Bathed and colored in red liquid again and again,
to the point where belligerence became second nature
And bloodlust sleeps within him.

The other was soft-spoken all around
Retiring and shy, blending in
He is more interested in keeping peace
than knowing other's business.
Smothered in an overarching shadow,
he has long struggled for his own identity
and recognition from the world.
Considerate, proud
He doesn't need decoration from others,
although acknowledgement would be nice.
Knowledge of romance is drilled into him,
but it doesn't mean he can use it well.
Unique, changing, flexible
He understands the want for space and time
and can bend to the needs of others.
Born in blood, forged through wars
Stained and tainted many times in crimson,
he still keeps his gentle, pacifying nature
And tames the beast that howls for destruction.

They are so different; you wouldn't believe they were brothers.

But Matthew and Alfred are brothers, in fact, they're twins.
They might be polar opposites, and they disagree a lot.
History has recorded conflicts and bloodshed between the two,
proof of the animosity that natural rivalry and politics create.
But they have always concurred on one thing; no one harms the other
without incurring the wrath of both.
It's an unspoken protective instinct between them;
One that brings out Matthew's hockey stick and terrifying face
And makes Alfred's mouth twitch into a smile that rivals Ivan's
"Harm him in any way and you die."

If there are inconsistencies with what the characters are supposed to look like, I would like to say the poem descriptions of America (Alfred) and Canada (Matthew) are of my own imagination. Well, not entirely. I've referenced both fan art and the original manga/anime so it is not like I completely created my own versions of the countries; however, I've noticed that in most versions of artwork, America and Canada often shared the same skin color and similar hair colors (which does make sense due to the fact that they are considered twins). That didn't sit very well with me though. So I made Canada's skin tone lighter than that of America's, it still is tan, just not as tan. I made his hair lighter as well because quite frankly, just because they are twins, doesn't mean they have to be identical. And Canada is from the north and I have this notion that northerners are lighter than southerners in general.

That is just an idea, not saying it is true.