"Jeg vil ha en oransje kjole."

Translation: I want an orange dress.

[m.g.doyle]

Oransje er den nye svart.

[Sheffio]

Why is it ha and not har?

[fveldig]

'ha' is part of the infinitive tense 'å ha', which is used after a modal verb such as 'kan', 'vil', 'må', etc...

'har' is the present tense.

[marcus..]

It will be discussed in a later topic.

[7jeny3]

At this point, I just look at it as
Vil ha = want.

[svenska1227]

When is "ønsker" used?

[TeemuLabura]

How do I say "Can I have an orange dress?" - Kan jeg ha en oransje kjole, takk?" Just curious...

[australsk]

I think your sentence can be used but it may depend upon the intention of your question. By this I mean if you are asking 'Am I allowed to have an orange dress?' or 'Do I have the option of having an orange dress?' I think your sentence may work with my first sentence whereas, I think the second would be 'Kan jeg få en oransje kjole'.

I am learning norsk so I may be way off with my suggestion and understanding but hopefully it may point you in the right direction to satisfy your curiosity.

Lykke til!

[rorytait]

Why is it "one orange dress" and not "a orange dress" ? I'm a bit confused how you would otherwise say "a orange dress" ...

[Deliciae]

"an orange dress" would have been accepted.

You use the indefinite article "a" before nouns that begin with a consonant sound, and "an" before nouns that begin with a vowel sound.