Custom Experience Orbs!

This mod allows you to change simple features of the experience orb entities, such as their color, pulse speed, and scale

Config - Screenshots

General Config Screen

Experience Orb Config Screen

Config - Explained

Scaling

Allows you to change the size of each experience orb, relative to their original size. Also gives you the option to scale the shadow of the experience orb along with the actual entity itself.
Colors & Pulse

Allows you to change the two main colors of an experience orb: main color and it's pulse color. By default Minecraft hard codes the experience orb colors between green (main color) and yellow (pulse color), and transitions between these two relative to the experience orb's age. With this mod you can also change the rate at which the speed of the orbs pulse between the two colors.

Setting the pulse rate to 0 will cancel out this pulsing functionality, always having the color as the main color.

Credits

Custom Experience Orbs