Repository: spyder-ide/spyder

Issue:
Spyder 4.2 tour dialog box not respecting light theme from previous spyder
## Description

### What steps will reproduce the problem?

<!--- You can use Markdown here --->

Starting Spyder 4.2 for the first time after upgrading from 4.1.5 where a light colour scheme theme was used, the new tour dialog box displays low contrast black text on a black background.



## Versions

* Spyder version: 4.2.0 
* Python version: 3.7.9
* Qt version: 5.9.6
* PyQt5 version: 5.9.2
* Operating System: Windows 10

### Dependencies

```

# Mandatory:
atomicwrites >=1.2.0            :  1.4.0 (OK)
chardet >=2.0.0                 :  3.0.4 (OK)
cloudpickle >=0.5.0             :  1.6.0 (OK)
diff_match_patch >=20181111     :  20200713 (OK)
intervaltree >=3.0.2            :  3.1.0 (OK)
IPython >=4.0                   :  7.18.1 (OK)
jedi =0.17.2                    :  0.17.2 (OK)
jsonschema >=3.2.0              :  3.2.0 (OK)
nbconvert >=4.0                 :  5.6.1 (OK)
numpydoc >=0.6.0                :  1.1.0 (OK)
paramiko >=2.4.0                :  2.7.2 (OK)
parso =0.7.0                    :  0.7.0 (OK)
pexpect >=4.4.0                 :  4.8.0 (OK)
pickleshare >=0.4               :  0.7.5 (OK)
psutil >=5.3                    :  5.7.2 (OK)
pygments >=2.0                  :  2.6.1 (OK)
pylint >=1.0                    :  2.6.0 (OK)
pyls >=0.36.1;<1.0.0            :  0.36.1 (OK)
pyls_black >=0.4.6              :  0.4.6 (OK)
pyls_spyder >=0.1.1             :  0.1.1 (OK)
qdarkstyle >=2.8                :  2.8.1 (OK)
qtawesome >=0.5.7               :  0.7.2 (OK)
qtconsole >=4.7.7               :  4.7.7 (OK)
qtpy >=1.5.0                    :  1.9.0 (OK)
rtree >=0.8.3                   :  0.9.4 (OK)
setuptools >=39.0.0             :  49.6.0.post20200814 (OK)
sphinx >=0.6.6                  :  3.2.1 (OK)
spyder_kernels >=1.10.0;<1.11.0 :  1.10.0 (OK)
three_merge >=0.1.1             :  0.1.1 (OK)
watchdog >=0.10.3               :  0.10.3 (OK)
zmq >=17                        :  19.0.1 (OK)

# Optional:
cython >=0.21                   :  0.29.21 (OK)
matplotlib >=2.0.0              :  3.3.1 (OK)
numpy >=1.7                     :  1.19.1 (OK)
pandas >=1.1.1                  :  1.1.1 (OK)
scipy >=0.17.0                  :  1.5.2 (OK)
sympy >=0.7.3                   :  1.6.2 (OK)

# Spyder plugins:
spyder_notebook                 :  0.3.0 (OK)
spyder_terminal                 :  0.4.2 (OK)
```



Discussion:
![Clipboard01](https://user-images.githubusercontent.com/4428426/98926425-33c04180-24cf-11eb-962c-1820c58a58ee.png)

Good point @gb119! We'll fix it in 4.2.1.
@juanis2112, I think we simply need to remove the background color of the dialog when we're using the light theme.

Resolving patch:
diff --git a/spyder/app/tour.py b/spyder/app/tour.py
--- a/spyder/app/tour.py
+++ b/spyder/app/tour.py
@@ -1437,16 +1437,14 @@ def __init__(self, parent, tour_function):
 
         # Buttons
         buttons_layout = QHBoxLayout()
-        if is_dark_interface():
-            start_tour_color = '#3775A9'
-            dismiss_tour_color = '#60798B'
-        else:
-            start_tour_color = '#9DA9B5'
-            dismiss_tour_color = '#CBCACA'
+        start_tour_color = '#3775A9'
+        dismiss_tour_color = '#60798B'
+        font_color = 'white'
         self.launch_tour_button = QPushButton(_('Start tour'))
         self.launch_tour_button.setStyleSheet(
           f"background-color: {start_tour_color};"
           f"font-size: {self.BUTTONS_FONT_SIZE};"
+          f"color: {font_color};"
           f"padding: {self.BUTTONS_PADDING}"
         )
         self.launch_tour_button.setAutoDefault(False)
@@ -1454,6 +1452,7 @@ def __init__(self, parent, tour_function):
         self.dismiss_button.setStyleSheet(
           f"background-color: {dismiss_tour_color};"
           f"font-size: {self.BUTTONS_FONT_SIZE};"
+          f"color: {font_color};"
           f"padding: {self.BUTTONS_PADDING}"
         )
         self.dismiss_button.setAutoDefault(False)


Test patch: