Background color utilities in Tailwind - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ selector

intermediate

Which Tailwind class sets a blue background with 50% opacity?

You want to apply a blue background color that is half transparent. Which class will do this correctly?

A bg-blue-500 bg-opacity-50

B bg-blue-500 opacity-50

C bg-opacity-50 bg-blue-500

D opacity-50 bg-blue-500

💡 Hint

Remember that background opacity is controlled by a separate utility in Tailwind.

The bg-blue-500 class sets the blue background color. The bg-opacity-50 class sets the background opacity to 50%. Using opacity-50 changes the opacity of the entire element, including text and borders, which is not what we want.

❓ rendering

intermediate

What background color will this Tailwind class produce?

Given the class bg-gradient-to-r from-red-400 via-yellow-300 to-green-500, what will the background look like?

Tailwind

<div class="bg-gradient-to-r from-red-400 via-yellow-300 to-green-500 h-24 w-full"></div>

A A solid red background

B A horizontal gradient from red to yellow to green

C A vertical gradient from red to yellow to green

D A horizontal gradient from green to yellow to red

💡 Hint

The to-r means the gradient goes to the right (horizontal).

The class bg-gradient-to-r creates a gradient background that moves horizontally from left to right. The colors start at red-400, pass through yellow-300 in the middle, and end at green-500 on the right.

🧠 Conceptual

advanced

Why should you prefer bg-opacity over opacity for background transparency?

Consider you want only the background color to be transparent but keep text fully visible. Which is the best reason to use bg-opacity instead of opacity?

A <code>bg-opacity</code> changes only background transparency, <code>opacity</code> affects the whole element including text and children

B <code>opacity</code> cannot be combined with background colors

C <code>bg-opacity</code> is faster to load in browsers

D <code>opacity</code> only works on images, not backgrounds

💡 Hint

Think about what parts of the element you want to see clearly.

The bg-opacity utility changes only the transparency of the background color, leaving text and other content fully visible. The opacity utility changes the transparency of the entire element, including text and child elements, which is usually not desired.

❓ layout

advanced

How to make a full-screen background color with Tailwind?

You want a background color that covers the entire browser window, even if the content is small. Which combination of classes achieves this?

A w-full h-full bg-blue-200

B h-full bg-blue-200

C min-h-screen bg-blue-200

D max-h-screen bg-blue-200

💡 Hint

Think about minimum height to fill the screen regardless of content size.

The min-h-screen class sets the minimum height to 100% of the viewport height, ensuring the background color covers the full screen even if content is small. h-full depends on parent height and may not fill the viewport if parents have no height.

❓ accessibility

expert

Which Tailwind background color utility best supports accessibility for text readability?

You want to ensure your background color provides enough contrast for text to be easily readable by all users. Which Tailwind background color class is best to use with white text for accessibility?

Tailwind

<div class="bg-??? text-white p-4">Accessible Text</div>

A bg-blue-100

B bg-yellow-200

C bg-pink-300

D bg-gray-900

💡 Hint

Dark backgrounds with light text usually have better contrast.

bg-gray-900 is a very dark background color that provides strong contrast with white text, making it easier to read for users with visual impairments. Lighter backgrounds like yellow-200 or blue-100 do not provide enough contrast with white text.