Paint bucket often doesn't fill areas as wanted, the edges can become more or less trashy. Photoshop has better tools for recoloring.
Seemingly your text already is a bitmap image and you have inserted a B&W adjustment layer, maybe to remove all color or to get the white and silver. The latter is impossible with B&W if there's only dark shades.
I would insert a new adjustment layer "Curves". With it you can invert black to white and create metallic effects if there's some greyscale gradients. As an adjustment layer it's non-destructive, so experiment freely. By having the "next layer only" switch =ON you can keep possible underlying layers intact.
An example: Black text on dark color background needs lightening:
With curves one can lift black to grey or white. This time the text has only black and transparency, so more variations are impossible with curves:
The "next layer only" -switch is ON to save the background.
With adjustment layer Hue&Saturation you can also affect colors. It can turn everything to grayscale, cause color shifts and colorize with a wanted color. I guess it's useless just in this case.
You should learn layer masks and layer styles. By having a white text on black in the layer mask you can for example make the text appear to be clipped from any material. Only get a photo of that material and put the text to the layer mask. With layer style Bevel & Emboss one creates metallic and 3D thickness effects with nearly zero effort. Drop shadow creates layer separation etc,etc,etc....
Here the preceding adjustment layer is merged to fix the effect. Layer style Bevel&Emboss creates some apparent thickness: