هاد البنطلون غامق بس لونه بهت.

Yes. هاد means this and points to something near the speaker.

In this sentence, هاد refers to البنطلون.

Depending on the region, you may also hear forms like هادا, هيدا, or feminine forms like هاي / هيدي. So the exact form can vary across Levantine dialects, but هاد is a very normal colloquial demonstrative.

Because in Arabic, when you say this + noun, the noun is usually definite too.

So:

• هاد البنطلون = this pair of pants / these pants
• not usually هاد بنطلون in this meaning

That is different from English, where this already makes the noun definite by itself. In Arabic, the noun typically still takes الـ.

Because Arabic treats بنطلون as a singular noun meaning one garment.

So even though English says pants or trousers, Levantine Arabic normally uses singular grammar:

• هاد البنطلون
• البنطلون غامق

You can think of it like English this pair of pants is... rather than these pants are.... Arabic is following the singular idea.

In Levantine Arabic, the present-tense verb to be is usually omitted.

So:

• هاد البنطلون غامق literally looks like this the-pants dark
• but it means this pair of pants is dark

The same thing happens in:

• لونه بهت = its color is faded

This is one of the most common features of spoken Arabic.

Because here they are predicate adjectives, not attributive adjectives.

Compare:

• البنطلون الغامق = the dark pants
• البنطلون غامق = the pants are dark

In your sentence, غامق and بهت are describing the noun as part of the statement, so they do not take الـ.

So:

• غامق = dark
• بهت = faded / pale / dull

not

• الغامق
• البهت

Here, بس means but.

So the sentence has two parts:

• هاد البنطلون غامق
• بس لونه بهت

Together: This pair of pants is dark, but its color is faded.

Important: بس can also mean only / just in other contexts. Learners often notice that one word has both meanings. Here, because it connects two contrasting ideas, it clearly means but.

لونه literally means his color or its color.

It is made of:

• لون = color
• ـه = his / its

Since البنطلون is a masculine noun, Arabic uses the masculine suffix ـه to refer back to it.

So:

• لونه = its color

In spoken Levantine, this is often pronounced something like lono or lawno, even if it is written لونه.

Usually, yes.

In more careful spelling, many people would write باهت, meaning faded, pale, dull. In casual colloquial writing, long vowels are often not written consistently, so you may see بهت for the same word.

So in this sentence:

• لونه بهت means
• its color is faded / washed out / dull

This kind of spelling variation is very common in informal Levantine writing.

They are both masculine singular, because they match the nouns they describe.

• غامق describes البنطلون, which is masculine singular
• بهت describes لون, which is also masculine singular

So the grammar is:

• البنطلون غامق
• لونه بهت

If the noun were feminine, you would usually hear feminine adjective forms, for example:

• هاي التنورة غامقة = this skirt is dark

Yes, it sounds natural.

You may hear small regional differences in both pronunciation and wording, for example:

• هاد البنطلون غامق بس لونو باهت
• هيدا البنطلون غامق بس لونو باهت

The main differences are:

• هاد / هيدا for this
• لونه / لونو in spelling
• بهت / باهت in spelling

But the structure and meaning stay the same.