Increases all stats while Isaac's active item is fully charged:
+0.25 speed.
+0.75 range.
+0.20 tears.
+0.10 shot speed.
+0.50 damage.
+1 luck.
Notes
The trinket creates no effect if Isaac has no active item.
Active items that are reusable indefinitely without a charge bar, such as How to Jump, will allow Vibrant Bulb's effects to be permanent (until the active item is swapped out).
Vibrant Bulb is slightly less than half as powerful as Dim Bulb; however, its effects are active more often.
Error: The given collectible ("Glowing Hour Glass") does not exist., when used, will not make the Vibrant Bulb inactive and will still provide the bonus until it has one bar of charge.
Having additional charge beyond full with The Battery does not provide an additional bonus. It does give an advantage however, since using the fully charged item once still provides Vibrant Bulb's effect.
If two active items are held (Schoolbag), the one currently active must be at full charge for the trinket to take effect (the other one doesn't need to be fully charged).
Bugs
Bug!
Replacing Isaac's active item with another active item that doesn't have a charge bar won't immediately activate the trinket's effects. The effect will depend on whether or not the previous item had a full charge or not. Furthermore, if the effect is active due to the previous item having a full charge, picking up a different active item that currently has no charge won't disable the effect, and vice-versa.
Active items that are reusable indefinitely without a charge bar, such as 
Active items that are reusable indefinitely without a charge bar, such as 
Bug!
Active Item Modifiers 
The Binding of Isaac: Rebirth
