`productListItem()`: color argument not applied to subtitle text and it becomes invisible

[admathis-col]

Description
When using productListItem in shinydashboardPlus, the styling driven by the color argument does not apply to the subtitle text. As a result, the subtitle is not visible in the UI, depending on the theme/background.

Reproducible example

library(shiny)
library(shinydashboard)
library(shinydashboardPlus)

shinyApp(
  ui = dashboardPage(
    dashboardHeader(),
    dashboardSidebar(),
    dashboardBody(
      box(
        title = "Product List",
        status = "primary",
        productList(
          productListItem(
            image = "https://www.pngmart.com/files/1/Haier-TV-PNG.png",
            title = "Samsung TV",
            subtitle = "$1800",
            color = "yellow",
            "This is an amazing TV, but I don't like TV!"
          ),
          productListItem(
            image = "https://upload.wikimedia.org/wikipedia/commons/7/77/IMac_Pro.svg",
            title = "Imac 27",
            subtitle = "$4999",
            color = "red",
            "This is were I spend most of my time!"
          )
        )
      )
    ),
    title = "Product List"
  ),
  server = function(input, output) { }
)
```