The blue color 3mm round top LED is a vibrant color that you can't go wrong with. The diffused frosty / milky style lens on these LEDs will help with diffusion, yet hide the color of the LED when it is turned off. This size led is commonly used in many custom projects, car lighting, models, and nearly every other project you can think of. They are also used for custom projects or in mass production products as well. This is a extremely popular size.
What sets this particular frosted LED apart from the other types of diffused LEDs is that the lens is simply frosted and not the color of the LED. In some circumstances it is more desirable to not see the color of the LED when the LED is turned off. This frosted or milky style lens will get the job done in this type of application. The frosted or milky style of diffusion usually provides a small edge over some of the colored diffused lenses in light diffusion/dispersion.
This size and type of led is so popular because it is bright, easy to use, small, and versatile. It can fit in most all spaces.
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