One of the most popular effects used for animated logos in film and television is the 'prestige' – a spotlight or shaft of light that traverses the text, sometimes accompanied by sparkling highlights.
This is not something you would want to do with an animated GIF, it 's too subtle and would require many high color-depth frames giving a huge file size. Using Flash, it is very easy!
All you need is the static white logo on one layer, and a travelling colored mask on the one below. The drop shadow and twinkling highlights are optional extras.
The mask needs to be twice the width of the logo but, because Flash limits the number of points you can have along a single gradient to eight, and we need quite a lot more than that for multiple shafts of light, the mask has to be constructed from multiple smaller elements which are then duplicated and grouped together to give the require width.
This is a single element of the mask repeated to make the whole mask shown below.
The mask positions tweened from the first to the last frames of the Flash movie
Each element is a trapezoid because the shafts of light are angled and the gradient is applied at the same angle as the ends. The gradient is made from a lowlight, a midtone a highlight, a midtone and back to a lowlight again. Don't make the lowlight colour too dark or the logo will be difficult to read.
In the example, I have used 120 frames at 12 fps so that the light glides across the logo slowly. The mask is motion tweened starting off at the left and moving to the right. In the first frame, the right hand side of the mask just covers the right hand side of the logo. In the final frame, the left side of the mask coincides with the left side of the logo.
The twinkling stars are little three frame movie clips where the star changes in size - 50%, 100% and 50% again and are placed fairly randomly on another layer and coinciding with highlights on the letters.
This movie is looped to repeat forever but you will probably only want the animated effect to happen once or twice.