#Mathematica, 63 94 103 bytes

When I first saw this challenge, I thought Sweet! Mathematica would be perfect for this! until I noticed that built-ins were banned :'(

But wait! I can use bar graphs!

r=RGBColor;BarChart[{1,1,1},ChartStyle->{r@"#0055a4",White,r@"#ef4135"},BarSpacing->0,AspectRatio->2/3]

(Thanks to Martin Büttner for shaving off 5 bytes but adding 16)

Looks like this:

If you add ,Axes->None it looks like this:

If you don't care about the border, you can use this: (95 bytes)

r=RGBColor;BarChart[{1,1},ChartStyle->{r@"#0055a4",r@"#ef4135"},BarSpacing->1,AspectRatio->2/3,Axes->None]

Looks like this:

Without axes:

Mathematica, 63 94 103 bytes

When I first saw this challenge, I thought Sweet! Mathematica would be perfect for this! until I noticed that built-ins were banned :'(

But wait! I can use bar graphs!

r=RGBColor;BarChart[{1,1,1},ChartStyle->{r@"#0055a4",White,r@"#ef4135"},BarSpacing->0,AspectRatio->2/3]

(Thanks to Martin Büttner for shaving off 5 bytes but adding 16)

Looks like this:

If you add ,Axes->None it looks like this:

If you don't care about the border, you can use this: (95 bytes)

r=RGBColor;BarChart[{1,1},ChartStyle->{r@"#0055a4",r@"#ef4135"},BarSpacing->1,AspectRatio->2/3,Axes->None]

Looks like this:

Without axes:

#Mathematica, 63 94 bytes

When I first saw this challenge, I thought Sweet! Mathematica would be perfect for this! until I noticed that built-ins were banned :'(

But wait! I can use bar graphs!

BarChart[{1,1,1},ChartStyle->{RGBColor["#0055a4"],White,RGBColor["#ef4135"]},BarSpacing->None]

Looks like this:

If anybody knows of any options for making the axes go away, let me know! Also, how do I "rename" symbols? RGBColor is too long.

#Mathematica, 63 94 103 bytes

When I first saw this challenge, I thought Sweet! Mathematica would be perfect for this! until I noticed that built-ins were banned :'(

But wait! I can use bar graphs!

r=RGBColor;BarChart[{1,1,1},ChartStyle->{r@"#0055a4",White,r@"#ef4135"},BarSpacing->0,AspectRatio->2/3]

(Thanks to Martin Büttner for shaving off 5 bytes but adding 16)

Looks like this:

If you add ,Axes->None it looks like this:

If you don't care about the border, you can use this: (95 bytes)

r=RGBColor;BarChart[{1,1},ChartStyle->{r@"#0055a4",r@"#ef4135"},BarSpacing->1,AspectRatio->2/3,Axes->None]

Looks like this:

Without axes:

#Mathematica, 63 bytes

When I first saw this challenge, I thought Sweet! Mathematica would be perfect for this! until I noticed that built-ins were banned :'(

But wait! I can use bar graphs!

BarChart[{1,1,1},ChartStyle->{Red,White,Blue},BarSpacing->None]

Looks like this:

If anybody knows of any options for making the axes go away, let me know!

#Mathematica, 63 94 bytes

When I first saw this challenge, I thought Sweet! Mathematica would be perfect for this! until I noticed that built-ins were banned :'(

But wait! I can use bar graphs!

BarChart[{1,1,1},ChartStyle->{RGBColor["#0055a4"],White,RGBColor["#ef4135"]},BarSpacing->None]

Looks like this:

If anybody knows of any options for making the axes go away, let me know! Also, how do I "rename" symbols? RGBColor is too long.