Learn German: Sie konnte den bunten Anzug nicht finden. - She could not find the colorful suit.

bunt modifies Anzug (suit), which is a masculine noun. In this sentence, the suit is the direct object (the thing being found), so it is in the accusative case. After the masculine accusative definite article den, the adjective takes an -en ending, becoming bunten.

Why is the verb finden at the very end of the sentence?

This is because of the modal verb konnte (could). In German, when a sentence uses a conjugated modal verb, that verb takes the normal second position, and the main action verb—in this case, finden (to find)—gets pushed to the very end of the sentence in its standard infinitive form.

Why is nicht placed right before finden instead of earlier in the sentence?

When negating an action in a sentence with a modal verb, nicht typically goes right before the main verb at the end of the sentence. Because she couldn't find the suit, nicht sits directly in front of finden to negate that specific action.

I remember that "can" is kann. What exact form is konnte?

konnte is the simple past tense of the modal verb können (to be able to / can). So while Sie kann means "She can", Sie konnte means "She could" or "She was able to".