Update app.py

app.py

@@ -64,7 +64,7 @@ def run_script(url: str, height: int, width: int, check_b,check_h):
             print (page.get_attribute('theme'))
             
             main_head = driver.find_element(By.CLASS_NAME, "main-content-header")
-            driver.execute_script("arguments[0].theme='gab-black';",main_head)
+            driver.execute_script("arguments[0].style.background='#474747';",main_head)
             
             head_shot = main_head.screenshot(f'head-{uid}-tmp.png')