Transparent Player Background
By default, the background of the embedded video player is transparent on Vimeo. All player elements (playbar, buttons, etc) are pinned to the video image, not the actual size of the iframe.
To avoid blank space in an embed, we recommend choosing a player size that matches your video's native aspect ratio. For example, if the original video has an aspect ratio of 16:9, you’ll want to embed the video with dimensions that yield an aspect ratio of 16:9, such as 800 x 450.
Important: the dimensions of the embedded player can also be influenced by the CSS styling established by your webpage. For videos embedded in a responsive design, make sure the height and width are both adjusting to the page’s width.
Turning off the transparent background
If your player displays differently than what you originally intended, you can disable the transparent background. To turn off the transparent background, add ?transparent=0 to the end of the player URL in your embed code. This parameter will force a black background and pin the player elements to the iframe, instead of the video image.
Example embed code:
<iframe src="https://player.vimeo.com/video/137805268?transparent=0" width="640" height="360" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>'
Applying a custom player background color
Instead of transparency or black bars, you can choose the exact color that appears in the background of the player. To apply a specific color, you’ll need to add the following inline style property to your iframe embed code:
FFFFFF is the color hex value for white, but you can search for the Hex code database for your desired color here- http://www.color-hex.com/
Example embed code:
<iframe src="https://player.vimeo.com/video/236787722" style="background-color: #FFFFFF" width="1000" height="400" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>