You can put a number in the $papercolor field when the form is first opened.
This is from the code in the Color Swatches database. You can set the field "ColorName" to the name you see in the InfoBox's Color Chooser and put this formula in the $papercolor field:
@Member(ColorName;
"black":
"white":
"red":
"green":
"blue":
"magenta":
"yellow":
"cyan":
"dark red":
"dark green":
"dark blue":
"dark magenta":
"dark yellow":
"dark cyan":
"gray":
"light gray":
"white":
"vanilla":
"parchment":
"ivory":
"pale green":
"sea mist":
"ice blue":
"powder blue":
"arctic blue":
"lilac mist":
"purple wash":
"violet frost":
"seashell":
"rose pearl":
"pale cherry":
"white":
"blush":
"sand":
"light yellow":
"honeydew":
"celery":
"pale aqua":
"pale blue":
"crystal blue":
"light cornflower":
"pale lavender":
"grape fizz":
"pale plum":
"pale pink":
"pale rose":
"rose quartz":
"5% gray":
"red sand":
"buff":
"lemon":
"pale lemon lime":
"mint green":
"pastel green":
"pastel blue":
"sapphire":
"cornflower":
"light lavender":
"pale purple":
"light orchid":
"pink orchid":
"apple blossom":
"pink coral":
"10% gray":
"light salmon":
"light peach":
"yellow":
"avocado":
"leaf green":
"light aqua":
"light turquoise":
"light cerulean":
"azure":
"lavender":
"light purple":
"dusty violet":
"pink":
"pastel pink":
"pastel red":
"15% gray":
"salmon":
"peach":
"mustard":
"lemon lime":
"neon green":
"aqua":
"turquoise":
"cerulean":
"wedgewood":
"heather":
"purple haze":
"orchid":
"flamingo":
"cherry pink":
"red coral":
"20% gray":
"dark salmon":
"dark peach":
"gold":
"yellow green":
"light green":
"caribbean":
"dark pastel blue":
"dark cerulean":
"manganese blue":
"lilac":
"purple":
"light red violet":
"light magenta":
"rose":
"carnation pink":
"25% gray":
"watermelon":
"tangerine":
"orange":
"chartreuse":
"green":
"teal":
"dark turquoise":
"light slate blue":
"medium blue":
"dark lilac":
"royal purple":
"fuchsia":
"confetti pink":
"pale burgundy":
"strawberry":
"30% gray":
"rouge":
"burnt orange":
"dark orange":
"light olive":
"kelly green":
"sea green":
"aztec blue":
"dusty blue":
"blueberry":
"violet":
"deep purple":
"red violet":
"hot pink":
"dark rose":
"poppy red":
"35% gray":
"crimson":
"red":
"light brown":
"olive":
"dark green":
"dark teal":
"spruce":
"slate blue":
"navy blue":
"blue violet":
"amethyst":
"dark red violet":
"magenta":
"light burgundy":
"cherry red":
"40% gray":
"dark crimson":
"dark red":
"hazelnut":
"dark olive":
"emerald":
"malachite":
"dark spruce":
"steel blue":
"blue":
"iris":
"grape":
"plum":
"dark magenta":
"burgundy":
"cranberry":
"50% gray":
"mahogany":
"brick":
"dark brown":
"deep olive":
"dark emerald":
"evergreen":
"baltic blue":
"blue denim":
"cobalt blue":
"dark iris":
"midnight":
"dark plum":
"plum red":
"dark burgundy":
"scarlet":
"60% gray":
"chestnut":
"terra cotta":
"umber":
"amazon":
"peacock green":
"pine":
"seal blue":
"dark slate blue":
"royal blue":
"lapis":
"dark grape":
"aubergine":
"dark plum red":
"raspberry":
"deep scarlet":
"70% gray":
"red gray":
"tan":
"khaki":
"putty":
"bamboo green":
"green gray":
"baltic gray":
"blue gray":
"rain cloud":
"lilac gray":
"light purple gray":
"light mauve":
"light plum gray":
"light burgundy gray":
"rose gray":
"80% gray":
"dark red gray":
"dark tan":
"safari":
"olive gray":
"jade":
"dark green gray":
"spruce gray":
"dark blue gray":
"atlantic gray":
"dark lilac gray":
"purple gray":
"mauve":
"plum gray":
"burgundy gray":
"dark rose gray":
"black") - 1