There's quite a few meanings I can draw from the use of color.
Context is important, and as we can read from the headline, the main article is about young Kurds fighting ISIS with guns and ideas. I think the "youth" and "ideas" parts are very relevant to the meaning of the colors.
Yellow is great for attracting attention, which as far as a magazine goes, is pretty important. The color itself has many meanings, here are some that I think really apply in this case:
Yellow is the color of sunshine. It's associated with joy,
happiness, intellect, and energy.
Yellow produces a warming effect, arouses cheerfulness,
stimulates mental activity, and generates muscle energy.
Use yellow to evoke pleasant, cheerful feelings.
Yellow is an unstable and spontaneous color, so avoid using
yellow if you want to suggest stability and safety.
The red color also has meaning. Granted, it contrasts nicely with the yellow, but other colors could as well.
From the same source as above:
Red is the color of fire and blood, so it is associated with
energy, war, danger, strength, power, determination as well as
passion, desire, and love.
Red is a very emotionally intense color. It enhances human
metabolism, increases respiration rate, and raises blood pressure.
It has very high visibility that’s why stop signs, stoplights,
and fire equipment are usually painted red.
So from the colors there's a feeling of instability, war, danger, and intensity yet at the same time we have these young Kurds, and youth is often associated with energy, innocence, joy, cheer, passion, desire, and spontaneity.
But who knows, I could be 100% off-target here.
After discussions with DA01 I feel like I should mention that the research behind the meanings is potentially questionable. People may have different personal meanings and it's not an exact science so I'd take it with a grain of salt. That being said the possibility still exists that these meanings played into the decision making, whether or not the meanings themselves are proven in any way.
Though after reviewing the other answers I'm inclined to lean towards the flag theory myself. Though flags themselves often have meaning behind the colors as well.
I'm personally very curious as to what meaning could be derived from the fact that the magazine cover is split 50/50. Why not 40/60, or 25/75?
Maybe it's the binary between "utopia" and "hell" or perhaps that the country itself is torn.
I wish I had more cultural insight as that may play a bigger role than anything I've mentioned so far.