• Bruises colour depend on healing: blue, red, purples, yellows, greens, browns, dark shades of the listed above.
• BLOOD appears darker in large amounts, brighter in small amounts OR when mixed with other fluids like saliva! When mixed with saliva, blood becomes STRINGY and the brightness lessens and becomes faint red/pink. In the face, blood occurs in more amounts because of the thickness/type of skin + more circulation etc. Because of this, trauma to the face will be more extreme (IE. a kick to the face will result in more bruising/swelling than getting kicked in the shin))
• BLOOD FOLLOWS CURVES, LIKE ANY OTHER FLUIDS!! To help you figure out curves, you can study facial planes!! 
• MUSCLES COLOURS ARE USUALLY PEACHY/PALE ORANGE despite race+skin type. In the first picture, the peaches by the wound on the bottom left, are colours of the muscles + flesh beneath the skin. The closer to the surface the wound is, the lighter the orange will be. A deep wound will be darker/peachy orange BUT there will be more blood!! ((see the cuts in first image, the darker bleeding one is a deeper cut))
• On shallow wounds, the blood will be much more bright red and because muscles are not FLAT+SMOOTH, they will run like a river through rocks ((around, etc.)) 
• The corner of a cut/wound will have darker blood as the blood supply is coming towards the exposed wound.  Blood gets DARKER with exposer + amounts. ((I.e. source: scabs)).
• If blood is frozen or dried, it will become DARKER! Frozen blood will appear a very dark red ((almost black!!)) 
• INTESTINES THAT ARE FRESH/connected to the body are PINK +WARM COLOURED!! Any intestines that are detached from the body or from a dead body will lose their warm hues as the body shuts down over time. Blood must be oxygenated to become RED. Blue blood is a result of not being oxygenated. A dead body will turn BLUE + SWELL. The organs seem to follow this as well. If you wish to show removed/dragged out insides, pale greys+blues are best to show the time out of the body. BRIGHT BLUES +EXAGGERATED BABY BLUES ARE TO BE AVOIDED FOR REALISTIC APPEAL!! ((Obviously if you’re doing art where you don’t care about the colour, then do as you’d like! If you’re going for realistic, the sentence above is best for a good outcome <3 ))

I heard you fell into a  R a b b i t  H o l e,,.