they are actually around the same color but light going through skin is absorbed differently the deeper the veins/arteries are. so the appereance of different color is just a measure of the deepness of said blood vessel. also arteries carry oxygen enriched bright red blood while veins carry oxygen deprived dark red blood, this difference is dark red vs bright red blood also contributes to the apparant change in color.
Arteries are red because they carry oxygenated blood (which is red) from the heart. Veins are blue because they return non-oxygenated blood back to the heart. Hemoglobin are the cells which carry oxygen in blood, and those cells change color depending on if they have oxygen or not. All blood looks red when someone bleeds, because when blue hemoglobin is exposed to air, it gets oxygen.
There isn't a difference. Blue and red may be traditionally used in charts but in real life, its all red. The blue just shows the arteries in the chart.
BLOOD IS ALWAYS RED.
It is always red
all blood is the same colour
reddish
The question is a little vague but I think it's referring to the difference in color between blood in the arteries and veins. Blood in the arteries is bright red. It is coming from the heart, by way of the lungs where it picks up oxygen, and then goes out to the tissues of the body to deliver it's oxygen. After the blood has delivered the oxygen it appears darker as it travels in the veins back to the heart. So "dark blood" would be found in the veins.
arteries.
arteries
In the arteries and arterioles.
oxygen
The capillaries are the smallest blood vessels and are usually found between arteries and veins.
arteries and veins are found throughout the body. arteries carry blood away from the heart and veins carry it to the heart
Inside the veins and arteries
Veins and arteries are found throughout the body. Veins transport "used" or de-oxygenated blood back to the heart whereas arteries deliver oxygenated blood throughout the body.
This is a false statement. While most of the arteries in the body carry oxygenated blood, the Pulmonary Arteries carry de-oxygenated blood from the Right Ventricle of the heart to the lungs.
pulmonary arteries
Arteries (except for the Pulmonary artery (which caries ed-oxygenated blood) and pulmonary vein (which carries oxygenated blood ))