Objects made with colored glass do not lose their transparency to light unless they are manufactured that way. There are a few glass items that are manufactured to keep out as much light as possible to preserve the contents within. Other than those few items, glass is a medium that lets light filter through it. This enables different views of the same substance with only a change in the amount of intensity of light passing through. For this reason, glass is an excellent medium for artists to use.
Artists rarely make objects with clear glass alone. The variations in color available in the modern world make it too tempting to add vibrant colors. These colors can be stand alone in an object, or they can be used with light. When by themselves, colored glass objects are beautiful and display their colors like proud peacocks. They can be monochrome, but this is generally not the case. When light is filtered through the glass objects, the view varies with the amount of light added and the density of the coloring in the glass.
Artists plan most of their works. They have a vision that is translated into a material object. Glass is no different from any other art in this respect. The artist knows what they want to achieve and how they need to do it. When working with glass, density of coloring is an important aspect. As light shines through, varying effects are created as a juxtaposition of the light and color density. This technique adds depth or it can show the motion by allowing gradients in the color. Versatility is the goal in when working with colored glass.
Artists today have a wide range of colors and densities in any glass project. Knowing how the coloring material will interact with the glass is how decisions on amount of color to be added. Each project requires the knowledge to mix the glass just the right amount to achieve varying color density in each piece of a project. It gives the gift of motion to an ocean wave or makes a glass animal appear ready to jump at the slightest sound. This type of art is still in the process of being created and appears to have a long, unbroken future ahead.