function getColor(value) {
const colors = {
0: '#F50000', 1: '#F50000', 2: '#F50000', 3: '#F50000', 4: '#F50000', 5: '#F50000', 6: '#F50000', 7: '#F50000', 8: '#F50000', 9: '#F50000',
10: '#F50000', 11: '#F50000', 12: '#F50000', 13: '#F50000', 14: '#F50000', 15: '#F50000', 16: '#F50000', 17: '#F50000', 18: '#F50000', 19: '#F50000',
20: '#F50000', 21: '#F50000', 22: '#F50000', 23: '#F50000', 24: '#F50000', 25: '#F50000', 26: '#F50000', 27: '#F50000', 28: '#F50000', 29: '#F50000',
30: '#F50000', 31: '#F50000', 32: '#F50000', 33: '#F50000', 34: '#F50000', 35: '#F50000', 36: '#F50000', 37: '#F50000', 38: '#F50000', 39: '#F50000',
40: '#F50000', 41: '#F50000', 42: '#F00000', 43: '#EB0000', 44: '#E60000', 45: '#E10000', 46: '#DC0000', 47: '#D70000', 48: '#D20000', 49: '#CD0000',
50: '#C80000', 51: '#C80A00', 52: '#C81400', 53: '#C81E00', 54: '#C82800', 55: '#C83200', 56: '#C83C00', 57: '#C84600', 58: '#C85000', 59: '#C85A00',
60: '#C86400', 61: '#C86E00', 62: '#C87800', 63: '#C88200', 64: '#C88C00', 65: '#C89600', 66: '#C8A000', 67: '#C8AA00', 68: '#C8B400', 69: '#C8BE00',
70: '#C8C800', 71: '#BEC800', 72: '#B4C800', 73: '#AAC800', 74: '#A0C800', 75: '#96C800', 76: '#8CC800', 77: '#82C800', 78: '#78C800', 79: '#6EC800',
80: '#64C800', 81: '#5AC800', 82: '#50C800', 83: '#46C800', 84: '#3CC800', 85: '#32C800', 86: '#28C800', 87: '#1EC800', 88: '#14C800', 89: '#0AC800',
90: '#00C800', 91: '#00CD00', 92: '#00D200', 93: '#00D700', 94: '#00DC00', 95: '#00E100', 96: '#00E600', 97: '#00EB00', 98: '#00F000', 99: '#00F500',
100: '#00FA00'
};
return colors[value];
}
function updateCircle() {
const button = document.getElementById('myButton');
const value = parseInt(button.innerText, 10);
const primaryColor = '#605BE5'; // primary color fixed
const secondaryColor = getColor(value);
button.style.backgroundImage = `linear-gradient(to bottom, ${primaryColor}, ${secondaryColor} 80%)`;
}
// Constantly update color
setInterval(updateCircle, 10);
<button id="myButton">1</button>