Go

package main

import "fmt"

type Color int
type CharStyle int
type SandGlassMod func(size int, char rune, str string) (int, rune, string)

const (
    Black Color = iota
    Red
    Green
    Brown
    Blue
    Purple
    Cyan
    Gray
)

const (
    Normal CharStyle = iota
    Bold
    Underlined
    Blinking
    Reverse
)

func printSandGlass(mods ...SandGlassMod) {
    // default values for size and char
    size, char := 8, '#'

    // apply functions to size and char
    for _, mod := range mods {
        size, char, _ = mod(size, char, "")
    }

    for lineNumber := 0; lineNumber < size; lineNumber++ {
        for columnNumber := 0; columnNumber < size; columnNumber++ {
            var symbol rune
            if (lineNumber == 0 || lineNumber == size-1) ||
                (columnNumber == lineNumber || columnNumber == size-lineNumber-1) {
                symbol = char
            } else {
                symbol = ' '
            }
            formatString := string(symbol)

            // apply functions to format string
            for _, mod := range mods {
                _, _, formatString = mod(0, 0, formatString)
            }
            fmt.Print(formatString)
        }
        fmt.Println()
    }
}

func main() {
    printSandGlass(setSandGlassChar('H'), setSandGlassSize(5),
        setCharStyle(Reverse), setBackgroundColor(Red), setForegroundColor(Blue))
}

func setForegroundColor(color Color) SandGlassMod {
    color += 30
    return func(size int, char rune, s string) (int, rune, string) {
        return size, char, fmt.Sprintf("\033[%dm%s\033[0m", color, s)
    }
}

func setBackgroundColor(color Color) SandGlassMod {
    color += 40
    return func(size int, char rune, s string) (int, rune, string) {
        return size, char, fmt.Sprintf("\033[%dm%s\033[0m", color, s)
    }
}

func setCharStyle(style CharStyle) SandGlassMod {
    return func(size int, char rune, s string) (int, rune, string) {
        return size, char, fmt.Sprintf("\033[%dm%s\033[0m", style, s)
    }
}

func setSandGlassSize(inputSize int) SandGlassMod {
    return func(size int, char rune, s string) (int, rune, string) {
        return inputSize, char, s
    }
}

func setSandGlassChar(inputChar rune) SandGlassMod {
    return func(size int, char rune, s string) (int, rune, string) {
        return size, inputChar, s
    }
}