I have been trying to create an automotive looking black guage with a orange hub and needle and noticed some "white speckles" so I tried an experiment. I set all the guage colors to black. The backplate is a black circle with white speckles on the outside rim. The hub is a black circle with white speckles on the outside rim. The text should be invisible but it is not. It appears to be very, very dark grey.

What you are seeing is the lack of anti-aliasing on curves in this gauge type. However, there are a couple of tricks that might help. For performance reasons, the default behavior of these drawing routines is to not "smooth" the circles. However in many cases you can trick the drawing system into smoothing by setting your color (for example your hub or outline color) to an alpha less than 255. Setting it to 254 or 253 will still be basically opaque BUT will switch on smoothing.

Second, consider drawing your gauge background using an Image. You can use Photoshop to create very good looking backplates for your gauge. Doing this actually will perform better because the system can simply draw an image rather than calculating and drawing your backplate on the fly.

We are already in the early stages of planning future releases and improvements to the quality of drawing is definitely on the list of features we are looking at.

Hope that helps.
Jake Pratt

Are all the elements of a radial guage dynamic or just the needle? In other works, is the entire guage redrawn? If so, how often? If not, which elements are redrawn and which are static?

Most of the rotary gauge is static. Only the needle is dynamic.