You're not showing us anything meaningful. Clearly the project is constructed from multiple layers and effects, but without seeing their order and what effects are used, nobody can tell you where to tweak, even more so as lighting effects use additive belnding which at some point will always turn white and makes tweaking colors a delicate process. I suggest you take it up with the original creator of the template or at least provide us with some screenshots of the timeline and effects settings...
Turn off visibility of layers until you find the layer that creates the flair. This may be one layer with an effect or it may be multiple solids with feathered masks, blurs, varying transfer modes. Then, either tell us what effect was used or apply Effect>Tint to the layer. The burst layer or layers are probably right under the bottom type or logo layer.
By the way, if you change the burst to blue it will be close to the same color as the background so it will be very hard to see.
I agree with Rick. I don't thinking changing the flare color is going to have the look you really want. Changing the flare from "hot blue white" to "blue" is going to make it considerably darker and far more saturated.
You can't have something really really bright (like a flare) that's also really saturated. It's really really really intensely bright blue light. The intense luminance blasts and bleaches the apparent color out of it. It's simulating the look of how additive colors interact.
Look at a roadside flare. Look at a halogen headlight. Look at a sodium vapor street light. While each one has a strong color cast to it, at the very center of the brightest core is almost completely white. It wouldn't be a bright flare if it wasn't ramping to white in the center.
Take a look at this Flickr seach for real lens flares. They all have an overall tint, but they could all be described as being nearly white in the center. They don't appear saturated in the core.
Europe, Middle East and Africa