colors.py

from kivy.app import App
from kivy.lang import Builder
from kivy.factory import Factory
from kivy.properties import ListProperty, NumericProperty


KV = '''
<Tile@Label>:
    bg_hue: 0
    font_size: sp(25)

    canvas.before:
        Color:
            hsv: self.bg_hue, app.saturation, app.value
        Rectangle:
            pos: self.pos
            size: self.size

BoxLayout:
    orientation: 'vertical'

    RecycleView:
        id: rv
        data: app.tiles
        viewclass: 'Tile'

        RecycleGridLayout:
            cols: int(len(rv.data) ** .5) + 1
            padding: sp(10)
            spacing: sp(10)

    BoxLayout:
        size_hint_y: None
        height: sp(48)
        Hues:
        Saturation:
        Value:


<Hues@BoxLayout>:
    orientation: 'vertical'
    Label:
        text: 'tiles'

    Slider:
        step: 1
        value: app.hues
        min: 1
        max: 100
        on_value: app.hues = self.value


<Saturation@BoxLayout>:
    orientation: 'vertical'
    Label:
        text: 'saturation'

    Slider:
        value: app.saturation
        min: 0
        max: 1
        on_value: app.saturation = self.value

<Value@BoxLayout>:
    orientation: 'vertical'
    Label:
        text: 'value'

    Slider:
        value: app.value
        min: 0
        max: 1
        on_value: app.value = self.value
'''

class Application(App):
    tiles = ListProperty()
    hues = NumericProperty(10)
    saturation = NumericProperty(.5)
    value = NumericProperty(.5)

    def build(self):
        return Builder.load_string(KV)

    def on_hues(self, inst, value):
        inc_hue = 1 / value
        self.tiles = [
            {
                'text': f'{x}: {inc_hue * x:.2f}',
                'bg_hue': inc_hue * x
            }
            for x in range(value)
        ]

if __name__ == "__main__":
    Application().run()