使用 PyGame 将基于百分比的颜色值从绿色更改为红色

我正在尝试制作一个健康栏，根据健康百分比将绿色缩放为红色。基本上，我试图使值 0.5 对应于 (255, 255, 0)，值 1.0 对应于 (0, 255, 0)，值 0.0 对应于 (255,0,0) 。我看见这个帖子 https://stackoverflow.com/questions/25943241/color-from-green-to-red-with-percentage，其意图与我相同，但在代码方面并没有太大帮助。同样适用于这个帖子 https://stackoverflow.com/questions/340209/generate-colors-between-red-and-green-for-a-power-meter.

这是我当前的代码：

def draw_player_health_mana(surface, x, y, curr_value, start_value, type_bar, font):
        #TRANSFORMS THE VALUES TO PERCENTAGE
        pct = curr_value/start_value
     
        if pct < 0:
            pct = 0
        #SIZE OF THE HEALTH BAR
        BAR_LENGTH = 150
        BAR_HEIGHT = 18
        
        #INITIAL COLOR VALUES
        red_color = 255
        green_color = 255
        
        #THE FILLED BAR TO DISPLAY VISUALLY OF CURRENT HP COMPARED TO MAX HP
        fill = pct * BAR_LENGTH
        
        #PYGAME RECTANGLES
        outline_rect = pg.Rect(x, y, BAR_LENGTH, BAR_HEIGHT)
        fill_rect = pg.Rect(x, y, fill, BAR_HEIGHT)

        #CHECKS WHAT TYPE OF BAR IS CALLED FOR - THERES MANA AND HEALTH
        if type_bar == 'health':
            #THE DIFFERENCE IN PERCENTAGE, MEANT AS AN INCREASE
            pct_diff = 1.0 - pct
            
            #INTENT IS TO CHECK IF PERCENTAGE IS ABOVE 50%, THEN DECREASE THE GREEN SPECTRUM
            #BUT AS SHOWN, IT NEVER DECREASES TO 0, BUT ONLY TO HALF OF 255...
            #LIKEWISE FOR THE INCREASE OF RED_COLOR 
            if pct > 0.5: 
                red_color = 255 * pct       #### Can't really figure out how to deal with this part 
            else:                                   
                green_color = 255*pct_diff
            
            col = (red_color, green_color, 0)
            print(col)
        elif type_bar == 'mana':
            col = BLUE

        pg.draw.rect(surface, col, fill_rect)
        pg.draw.rect(surface, BLACK, outline_rect, 2)
        
        text = font.render(str(curr_value) + "/" + str(start_value), True, BLACK)
        text_rect = text.get_rect(center=(BAR_LENGTH/2 + x, BAR_HEIGHT/2 + y))
        surface.blit(text, text_rect)

正如上面语法中所述，问题在于颜色转换。颜色为（红色、绿色、蓝色）。对于健康状况良好的漂亮绿色，它应该是 (0, 255, 0)。然而，当健康状况转向 50% 时，红色必须达到 255 的值（导致 (255, 255, 0)，我不知道如何有效地做到这一点，同时将绿色的减少过渡到 0 以达到更多的是红色..我在这件事上感到非常迷失，任何类型的帮助将不胜感激。

提前致谢。

0.5 对应 (255, 255, 0)，值 1.0 对应 (0, 255, 0) (255, 255, 0)，值 1.0 对应 (0, 255, 0)

因此绿色分量是min(255, pct_diff*2 * 255)红色分量是min(255, pct*2 * 255):

pct_diff = 1.0 - pct
red_color = min(255, pct_diff*2 * 255)
green_color = min(255, pct*2 * 255)
col = (red_color, green_color, 0)