As all of you remember from the first 3 movies, all of the transformers spill out some sort of red liquid that resemble blood when they got injured. But for some reason in AoE they have "predators's blood" instead. There are some notable scene:
- When Prime spin around before pointing his cannon at Cade and Tessa and says:"I'll kill you." Those blood spilled out from his chest. Or the most noticeable scene when his ear felf off
- Grimlock threw-up some when Prime climb on his arm and punch him in the face
- Or the scene from the trailer when Op slice a MAN-MADE cons into 2
This is out of the topic but even a man-made TF have blood too? WTF??

 

That is some kind of fluid or lubrifiant.It appears that both cybertronian TFs and Earth TFs need it

 

Yeah yeah, but they are supposed to be red like in the first films. But now they are green

 

Why don't you go ask Arcee sometime.
These films didn't care for continuity from day two (because day one there was nothing to be in continuity with).
I suppose this is one of the smaller things at least.

Don't take that first bit rudely I'm bashing the films (even though I liked the last two and thought 1 and two good bits)

 

so..

i'm not sure i understand the problem.. and i don't recall enough red liquid coming out of any of the transformers in the previous films to make it noticeable.

there are plenty of different colored lubricants that they could have running through them.. i don't understand why it would be a big deal.

 

I thought it was glowing blue stuff in the first movie *shrugs shoulders*

 

It was mainly Blue in he first movie. Which I was ok with because it was supposed to be Enegon (which is blue). In movie 2 we had the blue Energon, clear spit with some traces of green and they added in black oil-like fluids, some red when OP killed Blackout/Grindor. In movie 3 it was all the above but also adding in a lot of red liquids too. You see a lot of that when OP kills Megs at the end. And in this new movie it was mostly greens and blue.

Just wish they would have left it at the blue for Energon and if they want them to spit and stuff like that, ok but I didn't understand all the other color fluids being needed.

The human builds, I'm ok with Green as they were not intended to be running on Energon anyway.

 

Green is because they're environmentally friendly.

 

There are only three
-The blue stuff is the energy from their spark, it only come out when they got hit very close to the middle of their chest
-Orange is energon, of course but they are rarely seen. They only appear in ROTF
-The red oil (which i refer as blood) came out every time from everywhere since the second movie
But somehow in AOE the red oil is replaced by the green one. You should take notice more if you want to see them

I explained it above but i think Energon were never blue lol, they are orange. Remember what color is Optimus's Energon sword? and i totally didn't see the "traces of green" like you said in ROTF  
Yup, they are not supposed to be running on Engergon

 

ok, now that look more like booger   and that's not the green i was refering to

 

I guess the best explanation is that the KSI Fakeformers have some some nasty, dank green blood instead of the red blood from actual Decepticons like in ROTF and DOTM.

To be honest, I prefer that bright blue stuff from Blackout in the first movie.