The family of State of Being verbs (is/are/am/were/etc.) are used in this situation.
This does include the verb is, which is used correctedcorrectly in the sample sentence you provide. It may sound incorrect and imprecise to you, but it is normal and well-understood by a native speaker.
The road is bumpy.
The pie will be delicious when it is done.
I am happy.
Her shirt was purple.
More precise verbs can be used, but these are specific to the trait or quality in question.
The road looks/feels bumpy.
The pie will taste delicious when it is done.
I feel happy.
Her shirt looked purple.