title: Python3 & Kivy: widget's text color is set randomly as a default every run
body: <p>Here is my example (the code is the same, I ran code 2 times):</p>
  <p>first time screen: <img src="https://i.stack.imgur.com/OgrwY.png" alt="1" /></p>
  <p>second: <img src="https://i.stack.imgur.com/ziwQe.png" alt="2" /></p>
  <p>It doesn't depend on code. Everywhere I have the same problem, but ,anyway, I'll leave example code here:</p>
  <pre><code>from kivy.app import App
  from kivy.uix.button import Button
  from kivy.uix.gridlayout import GridLayout
  
  class ExampleApp(App):
      def build(self):
          bl = GridLayout(cols = 3)
          bl.add_widget(Button(text = &quot;button_0&quot;, font_size = 50))
          bl.add_widget(Button(text = &quot;button_1&quot;, font_size = 50))
          bl.add_widget(Button(text = &quot;button_2&quot;, font_size = 50))
          return bl
  
  if __name__ == '__main__':
      ExampleApp().run()
  </code></pre>
  <p>Command prompt:</p>
  <pre><code>[INFO   ] [Logger      ] Record log in C:\Users\User\.kivy\logs\kivy_19-05-24_51.txt
  [INFO   ] [Kivy        ] v1.10.1
  [INFO   ] [Python      ] v3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 21:26:53) [MSC v.1916 32 bit (Intel)]
  [INFO   ] [Factory     ] 194 symbols loaded
  [INFO   ] [Image       ] Providers: img_tex, img_dds, img_sdl2, img_gif (img_pil, img_ffpyplayer ignored)
  [INFO   ] [Text        ] Provider: sdl2
  [INFO   ] [Window      ] Provider: sdl2
  [INFO   ] [GL          ] Using the &quot;OpenGL&quot; graphics system
  [INFO   ] [GL          ] GLEW initialization succeeded
  [INFO   ] [GL          ] Backend used &lt;glew&gt;
  [INFO   ] [GL          ] OpenGL version &lt;b'4.5.0 - Build 23.20.16.5001'&gt;
  [INFO   ] [GL          ] OpenGL vendor &lt;b'Intel'&gt;
  [INFO   ] [GL          ] OpenGL renderer &lt;b'Intel(R) UHD Graphics 630'&gt;
  [INFO   ] [GL          ] OpenGL parsed version: 4, 5
  [INFO   ] [GL          ] Shading version &lt;b'4.50 - Build 23.20.16.5001'&gt;
  [INFO   ] [GL          ] Texture max size &lt;16384&gt;
  [INFO   ] [GL          ] Texture max units &lt;32&gt;
  [INFO   ] [Window      ] auto add sdl2 input provider
  [INFO   ] [Window      ] virtual keyboard not allowed, single mode, not docked
  [INFO   ] [Base        ] Start application main loop
  [INFO   ] [GL          ] NPOT texture support is available
  </code></pre>
  <p>p.s. it is the same both runs</p>
  <h1>pre-thanks</h1>