The difference between Yellow and Yellow-green

When used as adjectives, yellow means having yellow as its colour, whereas yellow-green means a bright yellowish-green colour.

Yellow is also noun with the meaning: the colour of gold, butter, or a lemon.

Yellow is also verb with the meaning: to become yellow or more yellow.

check bellow for the other definitions of Yellow and Yellow-green

Yellow as an adjective:

Having yellow as its colour.
Yellow as an adjective (informal):

Lacking courage.
Yellow as an adjective (publishing, journalism):

Characterized by sensationalism, lurid content, and doubtful accuracy.
Yellow as an adjective (chiefly, derogatory, offensive):

Far East Asian .
Yellow as an adjective (dated, Australia, offensive):

Of mixed Aboriginal and Caucasian ancestry.
Yellow as an adjective (dated, US):

High yellow.
Yellow as an adjective (UK, politics):

Related to the Liberal Democrats.

Examples:

"yellow constituencies"
Yellow as an adjective (politics):

Related to the of Germany.

Examples:

"the black-yellow coalition"

Yellow as a noun:

The colour of gold, butter, or a lemon; the colour obtained by mixing green and red light, or by subtracting blue from white light.
Yellow as a noun (US):

The intermediate light in a set of three traffic lights, the illumination of which indicates that drivers should stop short of the intersection if it is safe to do so.
Yellow as a noun (snooker):

One of the colour balls used in snooker, with a value of 2 points.
Yellow as a noun (pocket billiards):

One of two groups of object balls, or a ball from that group, as used in the principally British version of pool that makes use of unnumbered balls (the (yellow(s) and red(s)); contrast stripes and solids in the originally American version with numbered balls).
Yellow as a noun (sports):

A yellow card.

Yellow as a verb (intransitive):

To become yellow or more yellow.
Yellow as a verb (transitive):

To make (something) yellow or more yellow.