Does the 8A have a blue base or purple? Searched everywhere online but cannot find the answer!

The base for 8A is blue. In case you want to add - Each color is formulated specially for the level, so not all A's in Wella Color Charm are blue based.

How many oz of activating lotion do I use? And do I use a full tube in one coloring? (hair not super long).

My mother was a hairdresser for 30 years and I have always added twice the amount of Wella Color Charm Cream 20 Volume 32 oz. Developer with the whole bottle of color which is only 1 1/2 oz. You will have about 5 oz. of color. I have short thin hair and it takes just about the whole bottle. One note, the tube color is thicker and doesn't run like the liquid.

Is this hair color tube 2oz and i order activating lotion 4oz separately? mix them and apply how - does it have a squeeze bottle? sorry i am a guy

You purchase each separately. If you’re going to do this regularly, get as big a bottle of activating lotion as you can. Squeeze bottle is separate too. Squeeze bottle should have measuring markings so you can get the proportions correct. Mix color and activating lotion thoroughly in the squeeze bottle by shaking vigorously (with your finger over the top so it doesn’t spray all over.). I’ve been coloring my roots with these products for decades. I often mix dark brown with some golden browns and or a little of a dark reddish.

Puedo mezclar wella 8 a con wella 5 n. esto ayudaría a quitar manchas naranjas y rubias por decoloración ?

This is a great question. When using the 8A that will take care of the orange however 5N will not assist in toning at all and bring you down to a darker level of hair. 8 is going to be blonde. You need to get violet in the formulation to assist with toning out yellow. So no the formulation you gave me will not assist in what you are trying to achieve.