I know this is not a good answer, but the Danish vikings also had a red banner (with a black raven on it), so when the current flag was adopted in the 12th century, it was probably natural to choose red as the main colour. Apart from that red is of course a very visible signal colour, which is used in the flags of many countries.
the red means the blood of soldiers and the white means the ghost of anderson
According to legend, a red flag with a white cross fell from heaven. Roman Emperor Constantine had a dream that this flag would make him victorious. The white cross was for Christianity.
Red flag with a white cross
Red stands for hardiness, bravery, valour &strenghtWhite stands for peace and honesty
Dannebrog
They are not representing anything. The story goes, that the danish flag fell from the heaven under a war. It probably did, but historians say the flag was an ideal wrapping for one of those long-distance catapult-bombs.
The flag of Greenland is red and white, the same as the colours of the Danish flag. http://upload.wikimedia.org/wikipedia/commons/thumb/9/94/Flag_of_Greenland_(bordered).svg800px-Flag_of_Greenland_(bordered).svg.png
Flags in the early times had the function of rallying people in battle and showing them where their side was fighting and heading. So many flags had a 'signal' color like red to draw attention. That is also why the Danish flag is red. The white cross represents Christianity and can in similar form also be found in the flags of the other Scandinavian countries. Legend has it that the Danish flag fell out of the sky as a sign of Heaven during the battle of Lyndanisse, in 1219.
red and white (if you consider white a colour) so 50% each
Blue with a red cross outlined in white extending to the edges of the flag; the vertical part of the cross is shifted to the hoist side in the style of the Dannebrog (Danish flag).It is mainly blue, with a red cross on a white cross in it too.
Unfortunately it is not the Danish flag, but a crusader flag. The flag in the Church is not only a flag, it is a Royal or a flag the government use, when there is something to celebrate in the Royal family or visiting from other states. All official buildings use it in that case.
Is small
The oldest flag still used by a nation, is the danish flag Dannebrog.
It is the oldest NATIONAL flag still in use - it is not the oldest flag.