Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper or aluminum foil. Arrange the saltine crackers in a single layer to cover the baking sheet.
In a saucepan over medium heat, melt the butter and brown sugar together, stirring constantly. Once it starts to boil, continue stirring for about 3 minutes.
Pour the hot toffee mixture evenly over the saltine crackers, using a spatula to spread it out if necessary.
Bake for 5 minutes, until the toffee is bubbling.
Remove from the oven and immediately sprinkle the white chocolate chips over the hot toffee. Let them sit for a few minutes to soften, then spread evenly with a spatula. If using food coloring, mix it into the melted chocolate before spreading.
Add Easter-themed sprinkles and candies on top while the chocolate is still soft.
Let the bark cool completely at room temperature or refrigerate for about 1 hour until firm.
Once set, break into pieces and enjoy!