The bark coloration is present throughout the tree's lifespan. However, much like a coral bark maple, the red snakebarks tend to have the most intense coloring on the newest growth.

Here's one of my Acer capillipes showing what gardengal describes.

Of the familiar ones only A. tegmentosum remains well striped to the ground.

I disagree. Acer conspicuum remains very distinctly striped throughout its lifespan. But while the striping remains very distinct, the bark does not remain the very intense red of the newest growth but fades to a more orangey-gold color.......but with very visible white stripes.