Το μωβ δεν ταιριάζει με όλα, αλλά μου αρέσει πολύ.

μωβ means purple, and here it is being used as a noun: the color purple.
That is why it takes the neuter article το.

So:

• μωβ = purple
• το μωβ = the color purple / purple as a thing

Greek often uses the article with colors when talking about them as concepts.

Here it functions as a noun: purple as a color in general.

In other contexts, μωβ can also work like an adjective:

• το μωβ φόρεμα = the purple dress

A useful thing to know is that μωβ is usually treated as indeclinable, meaning its form does not normally change for gender, number, or case.

Because the subject is το μωβ, which is singular.

So the structure is:

• Το μωβ = subject
• δεν ταιριάζει = does not match / does not go

ταιριάζει is the third person singular form, matching το μωβ.

ταιριάζω με means to match, to go with, or sometimes to suit.

In this sentence:

• Το μωβ δεν ταιριάζει με όλα
  = Purple doesn’t go with everything / Purple doesn’t match everything

The preposition με means with, so literally it is something like:

• Purple does not match with everything

όλα means everything here.

It is the neuter plural form of όλος and is often used by itself to mean all things / everything.

So:

• με όλα = with everything

Even though όλα is grammatically plural in form, in English the natural translation is usually everything, not all things.

Because Greek often prefers a simple verb where English might also use a phrase.

• δεν ταιριάζει = it doesn’t match / it doesn’t go well
• δεν είναι ταιριαστό would mean something more like it is not suitable/fitting, which is possible in some contexts but less natural here

So ταιριάζει is the most natural choice for colors, clothes, styles, and combinations.

Yes, exactly. Greek αρέσω works differently from English like.

Greek expresses the idea as:

• μου = to me
• αρέσει = is pleasing

So:

• μου αρέσει = I like it

This is one of the most important Greek patterns to get used to.
The person who likes something is in an indirect-object form:

• μου αρέσει = I like it
• σου αρέσει = you like it
• του/της αρέσει = he/she likes it

μου means to me.

In αλλά μου αρέσει πολύ, the subject of αρέσει is understood from context: it is το μωβ.

So the full idea is:

• but purple is very pleasing to me
• natural English: but I like it a lot

Greek often leaves the repeated subject unstated when it is obvious.

Because the thing being liked is singular: το μωβ.

Compare:

• Μου αρέσει το μωβ. = I like purple.
• Μου αρέσουν τα χρώματα. = I like the colors.

So the verb agrees with the thing that is pleasing, not with the person who likes it.

πολύ here means a lot or very much.

So:

• μου αρέσει πολύ = I like it a lot / I like it very much

Putting πολύ at the end is very natural in Greek. It modifies the whole idea of liking.

Common patterns:

• Μου αρέσει πολύ. = I like it a lot.
• Μου αρέσει πάρα πολύ. = I like it very, very much.

Because αλλά means but, and it connects two contrasting clauses:

• Το μωβ δεν ταιριάζει με όλα
• αλλά μου αρέσει πολύ

The comma helps mark that contrast, just as in English:

• Purple doesn’t go with everything, but I like it a lot.

Yes. πάει με can also mean goes with, especially in everyday speech.

So these are both natural:

• Το μωβ δεν ταιριάζει με όλα.
• Το μωβ δεν πάει με όλα.

A rough difference:

• ταιριάζει με can sound a bit more like matches / suits
• πάει με can sound a bit more conversational, like goes with

Both work well for colors and clothing.

You could say:

• Το μωβ δεν ταιριάζει με όλα, αλλά εμένα μου αρέσει πολύ.

Adding εμένα gives emphasis:

• but I like it a lot
• more literally: but as for me, I like it a lot

Greek often adds these stressed pronoun forms for contrast or emphasis.