الحيطة رمادية.

A natural Egyptian pronunciation is:

el-ḥēṭa ramādiyya

A rough guide:

• el- = the
• ḥēṭa = wall
• ramādiyya = gray

A very loose English approximation would be:

• el-HAY-ta ra-MAA-dey-ya

But the Arabic sounds are not exactly the same as English ones, especially ḥ and ṭ.

الـ is the Arabic definite article, meaning the.

So:

• حيطة = a wall / wall
• الحيطة = the wall

In Egyptian Arabic, الـ is usually pronounced el- or il-, even though learners often first see it written as al-.

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

So:

• الحيطة رمادية literally looks like the wall gray
• but it means The wall is gray

This is completely normal in both Egyptian Arabic and Standard Arabic for simple present-tense sentences.

If you wanted was or will be, then Arabic would usually use an actual verb.

Because here رمادية is the predicate, not an adjective inside a noun phrase.

Compare:

• الحيطة رمادية = The wall is gray
• الحيطة الرمادية = the gray wall

This is a very important difference:

• noun + adjective without الـ on the adjective can form a full sentence: The wall is gray
• noun + adjective with matching definiteness forms a noun phrase: the gray wall

So in your sentence, رمادية does not take الـ.

Because الحيطة is grammatically feminine, and adjectives in Arabic must agree with the noun they describe or predicate.

So:

• masculine: رمادي = gray
• feminine: رمادية = gray

Since حيطة is feminine, you say:

• الحيطة رمادية

If the noun were masculine, you would use رمادي instead.

Yes, حيطة is a very common Egyptian Arabic word for wall.

You may also hear:

• جدار — more formal / more Standard Arabic-like
• حائط — Standard Arabic and also understood, but less everyday-colloquial in Egypt than حيطة

So for natural everyday Egyptian speech, حيطة is a very good choice.

The two sounds English speakers often notice are:

• ح in الحيطة
• ط in الحيطة

ح:

• This is a stronger, breathier sound than normal English h
• It comes from deeper in the throat

ط:

• This is an emphatic or heavy t
• Your tongue position is similar to t, but the sound is darker/heavier

So حيطة is not quite like plain English heeta or hita. The consonants are more distinctly Arabic.

That is the normal pattern in Arabic.

For this kind of sentence, Arabic commonly uses:

subject + predicate

So:

• الحيطة = the wall
• رمادية = gray

Together:

• الحيطة رمادية = The wall is gray

Arabic generally puts adjectives and descriptive words after the noun, not before it like English often does.

الحيطة رمادية is the normal, neutral way to say The wall is gray.

In speech, word order can sometimes change for emphasis, but for a basic statement, this order is the most natural:

• الحيطة رمادية

You may also hear other everyday Egyptian ways to express a similar idea, such as:

• لون الحيطة رمادي = The wall’s color is gray
• الحيطة لونها رمادي = The wall, its color is gray

But your original sentence is simple, correct, and natural.