Bright Yellow

Bright Yellow is a common color used in many LEGO products. It is most used in Part 3626 and its variations. Yellow is the color of most non-licensed minifigures. According to professional LEGO builder Ryan McNaught, it is also the most common color used in LEGO sets.
This is one of the six original LEGO colors. The others are Black, White, Bright Blue, Bright Red, and Dark Green.