How many colors?
Apart from the green and white background, how many colors can you see?
有几种颜色？
除了绿色和白色的背景，你还能看到几种颜色？
It may look as if the two arms of the 'X' use different shades of pink,
but in fact the whole X only uses a single color.
How can this be true?
看上去组成“X”的两条线段是由不同深浅的两种粉色组成，但事实上，整个“X”只用了一种颜色。这怎么可能？