@CanadianSteel, take a look at anything with white LEDs including flashlights and even factory LED DRL and headlights. The emitter has the yellow phosphor. Here's an example of a bare white LED emitter, which is typically the same ones used for DRLs (tiny). It's yellow:
Cool White (5650K), SinkPAD-II Square LED - 235lm
You can probably use spray tint. The curvature of the lens makes it difficult to apply a film over it.