Use int16 for spy_colors dtype

Author: tboggs

spectral/config.py

@@ -157,4 +157,4 @@ class SpySettings:
                        [100, 0, 100],
                        [200, 0, 200],
                        [0, 100, 100],
-                       [0, 200, 200]], np.int8)
+                       [0, 200, 200]], np.int16)