coloring histogram with multiple colors where each color has a specified range - matplotlib

Question

I was trying to load an excel data into python and plot it as a histogram. My aim would be to color the histogram according to specific ranges: every number smaller than 4 = yellow, numbers between 4 and 12 = orange and so on. I encountered 2 problems I don´t have 4 separate histograms the programm plots everything in 1 graph. Second problem,one of the loops, obviously is wrong because it only shows everything in yellow.
Could somebody help me out which loop is wrong and why? Is there a better way to do this?I appriciate every help im pretty new at programming.
import matplotlib.pyplot as plt
import pandas as pd
import openpyxl
# Load the workbook
path='C:/Users/akosw/OneDrive/Desktop/Programmieren/Geotechnikstammdaten.xlsx'
#workbook = openpyxl.load_workbook("Geotechnikstammdaten.xlsx","C:/Users/akosw/OneDrive/Desktop/Programmieren")
workbook = openpyxl.load_workbook(path)
# Select the sheet
sheet = workbook['Tabelle3']
# Extract the values from each column
columns = [[cell.value for cell in column] for column in zip(*sheet.rows)]
# Iterate over the columns
for i, values in enumerate(columns):
# Create the histogram
plt.hist(values, bins=50)
# Color the bars according to the specified rules
for patch in plt.gca().patches:
if patch.get_height() < 4:
patch.set_facecolor('yellow')
elif patch.get_height() < 12:
patch.set_facecolor('orange')
elif patch.get_height() < 26:
patch.set_facecolor('green')
elif patch.get_height() < 51:
patch.set_facecolor('blue')
else:
patch.set_facecolor('red')
plt.title(f'Column {i+1}')
plt.show()
# Save the histogram to a file
# plt.savefig(f'histogram_{i+1}.png')
Here is kind of what im trying to achiev but instead of a bar chart i want a histogramm.
from bisect import bisect
import matplotlib.pyplot as plt
import numpy as np
OM_VALUES = [4, 12, 26, 51]
OM_COLORS = ["yellow", "orange", "blue", "green", "red"]
data = [4, 6, 7, 7, 11, 16, 23, 30, 30, 27, 1, 3, 4, 33, 37, 39, 45, 51]
labels = range(len(data))#[0,1,2,3,4,5,6,7,8,9,10,11]
plt.barh(labels, data,height=1.0, color=[OENORM_COLORS[bisect(OENORM_VALUES, v)] for v in data])
plt.title('Counts per depth')
plt.xlabel('Value')
plt.ylabel('Depth')
#plt.savefig('counts_depth.png')
plt.show()