diff --git a/map2map/utils/figures.py b/map2map/utils/figures.py
index 2a2f08c..03d8b7e 100644
--- a/map2map/utils/figures.py
+++ b/map2map/utils/figures.py
@@ -1,5 +1,4 @@
 from math import log2, log10, ceil
-import warnings
 import torch
 import numpy as np
 import matplotlib
@@ -46,15 +45,14 @@ def plt_slices(*fields, size=64, title=None, cmap=None, norm=None):
     )
 
     for f, (field, cmap_col, norm_col) in enumerate(zip(fields, cmap, norm)):
-        all_non_neg = (field >= 0).all()
-        all_non_pos = (field <= 0).all()
+        all_non_neg = np.all(field >= 0)
+        all_non_pos = np.all(field <= 0)
 
         if cmap_col is None:
             if all_non_neg:
-                cmap_col = 'viridis'
+                cmap_col = 'inferno'
             elif all_non_pos:
-                warnings.warn('no implementation for all non-positive values')
-                cmap_col = None
+                cmap_col = 'inferno_r'
             else:
                 cmap_col = 'RdBu_r'
 
@@ -68,8 +66,12 @@ def plt_slices(*fields, size=64, title=None, cmap=None, norm=None):
                 else:
                     norm_col = LogNorm(vmin=quantize(l2), vmax=quantize(h2))
             elif all_non_pos:
-                warnings.warn('no implementation for all non-positive values yet')
-                norm_col = None
+                if l1 < 0.1 * l2:
+                    norm_col = Normalize(vmin=-quantize(-l2), vmax=0)
+                else:
+                    norm_col = SymLogNorm(linthresh=quantize(-h2),
+                                          vmin=-quantize(-l2),
+                                          vmax=-quantize(-h2))
             else:
                 vlim = quantize(max(-l2, h2))
                 if w1 > 0.1 * w2 or l1 * h1 >= 0: