Continous color table for heatmap

my values range from negative to positive, zero being in the middle not at the lowest value. How can I just threshold 0, or a range like (-0.0001, 0.00001) ?
There are values close 0 on either side, and they are not discernible if 0 is rendered in the overlay
For example this is the full range

negative only (-0.3 to -0.01)

positively only (0.01 to 0.9)

I want the last two together in the same image.