Minecraft wiki entry for World_border, associated text: The world border is tinted depending on how how size changes. When the border is not moving, the stripes are a translucent aqua color. If the border is expanding, the stripes appear green (the translucency of this green is unknown); if the border is shrinking, the lines appear red (the translucency of this red is also unknown). If the world border is moving but its size is not changing, what color it appears as is unknown.[more information needed]