fix: adding random colour generator

LoopStructural/utils/colours.py

@@ -0,0 +1,26 @@
+from LoopStructural.utils import rng
+
+
+def random_colour(n: int, cmap='tab20'):
+    """
+    Generate a list of random colours
+
+    Parameters
+    ----------
+    n : int
+        Number of colours to generate
+    cmap : str, optional
+        Name of the matplotlib colour map to use, by default 'tab20'
+
+    Returns
+    -------
+    list
+        List of colours in the form of (r,g,b,a) tuples
+    """
+    import matplotlib.cm as cm
+
+    colours = []
+    for _i in range(n):
+        colours.append(cm.get_cmap(cmap)(rng.random()))
+
+    return colours